Antiarrhythmic 2,2-dialkyl-1-(aminoalkyl)-spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-diones
The present invention relates to hydantoin derivatives having excellent medicinal effects. More particularly, the invention relates to hydantoin derivatives having the following general formula and pharmaceutically acceptable acid addition salts thereof: ##STR1## wherein X 1  and X 2  can be the same or different and each represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, trifluoromethyl, trifluoroethoxy or a nitro group, or X 1  and X 2  together form an alkylenedioxy group (--O--R--O--) connected to adjacent carbon atoms in the ring; R 1  and R 2  can be the same or different and each represents a hydrogen atom or a lower alkyl group, or R 1  and R 2  together with the carbon atom to which they are bonded form a C 5  or C 6  cycloalkyl group; Z represents (a) a group of the formula: ##STR2## in which R 3  and R 4  can be the same or different and each represents a hydrogen atom, a lower alkyl group, a hydroxyalkyl group or a substituted or unsubstituted aralkyl group, or R 3  and R 4  together with the nitrogen atom to which they are bonded, form a C 5  or C 6  saturated heterocyclic group, which heterocyclic ring can further contain an oxygen atom or a nitrogen atom and may have a substituent such as a C1-C6 lower alkyl and an aryl on the nitrogen atom, (b) a group of the formula: ##STR3## in which R 5  and R 6  can be the same or different and each represents a hydrogen atom, a phenyl group or a group of the formula: --OR 7  (R 7  being a hydrogen atom, an acyl group, a lower alkyl group or a substituted or unsubstituted aralkyl group) or R 5  and R 6  together with the carbon atom to which they are bonded form a 4-membered or 5-membered cyclic group containing two oxygen atoms, or R 5  and R 6  together form a group of the formula: ═O, or (c) a group of the formula: ##STR4## and n represents an integer of 2 to 7; processes for the production thereof; and antiarrhythmic agents containing them as an active ingredient. 
     Definitions of terms used herein will now be described. 
     The term &#34;lower&#34; refers to a group having 1 to 6 carbon atoms unless otherwise stated. 
     The term &#34;lower alkyl group&#34; in the definition of X 1 , X 2 , R 1 , R 2 , R 3 , R 4  and R 7  includes straight-chain and branched alkyl groups, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl and hexyl groups. Among them, alkyl groups having 1 to 6 carbon atoms are preferred and those having 1 to 3 carbon atoms are particularly preferred. 
     The term &#34;halogen atom&#34; in the definition of X 1  and X 2  includes, for example, fluorine, chlorine and bromine atoms. 
     The term &#34;lower alkoxy group&#34; in the definition of X 1  and X 2  includes straight-chain and branched lower alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentyloxy, isopentyloxy and hexyloxy groups. The alkylenedioxy groups formed by X 1  and X 2  together with adjacent carbon atom(s) on the benzene ring include, for example, methylenedioxy and ethylenedioxy groups. 
     The term &#34;aralkyl groups&#34; in the definition of R 3  and R 4  includes, for example, benzyl, phenethyl and 3,4-dimethoxyphenethyl groups. 
     The term &#34;C5 or C6 saturated heterocyclic group&#34; includes for example morpholino and piperazyl. Piperazyl group may have a substituent on the aryl portion, such as an aryl group and C1 to C6 lower alky group. 
     The pharmaceutically acceptable acid addition salts of the hydantoin derivatives of the present invention include salts thereof with inorganic acids such as phosphoric acid, hydrochloric acid, sulfuric acid, hydrogen bromide and hydrogen iodide, and organic acids such as fumaric acid, oxalic acid, acetic acid, methanesulfonic acid, lactic acid, citric acid, tartaric acid and succinic acid. 
     Typical examples of processes for producing the intended compounds (I) of the present invention will now be given. These processes are shown by the following flow sheet: ##STR5## wherein X and Y each represents a halogen atom, such as chlorine or bromine, and X 1 , X 2 , R 1 , R 2 , R 5 , R 6  and n have the same meanings as set forth above. 
     Namely, a compound of general formula (II) is reacted with a compound of general formula (IV) to obtain a compound of general formula (III) (step A) and then the compound of formula (III) is reacted with a compound of general formula (V), (VI) or (VII) to obtain an intended compound of formula (I) (step B). 
     In another process, a compound of general formula (II) is reacted with a compound of general formula (VIII), (IX) or (X) to form an intended compound of formula (I) (step C). 
     Now, the description will be made on the respective reaction steps. 
     REACTION STEP A 
     Process 1 
     A compound of general formula (II) is reacted with sodium hydride, potassium hydride, calcium hydride or sodium amide in a solvent such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, diethyl ether, tetrahydrofuran or acetonitrile under cooling with ice or at room temperature and the reaction product is reacted with a compound of general formula (IV) to obtain a compound of general formula (III). 
     Process 2 
     A compound of general formula (II) is reacted with a sodium or potassium alcoholate such as sodium methylate, sodium ethylate, potassium methylate or potassium ethylate in a solvent such as methanol, ethanol, isopropanol, butanol, dimethylformamide, dimethylacetamide, diethyl ether, dioxane, tetrahydrofuran or acetonitrile under cooling with ice or at room temperature and the reaction product is reacted with a compound (IV) to obtain a compound of general formula (III). 
     Process 3 
     A compound such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, triethylamine, diisopropylethylamine, dimethylaminopyridine or pyridine is added to a compound of general formula (II) in a solvent such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, diethyl ether, dioxane, tetrahydrofuran, acetonitrile, acetone, methyl ethyl ketone, methanol, ethanol, isopropanol or butanol. The resulting compound is reacted with a compound of general formula (IV) at room temperature or under reflux to obtain a compound of general formula (III). 
     REACTION STEP B 
     Process 1 
     A compound of general formula (V), (VI) or (VII) is added to a compound of general formula (III) in a solvent such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, diethyl ether, dioxane, tetrahydrofuran or acetonitrile. Then, a compound such as sodium hydride, potassium hydride, calcium hydride or sodium amide is added thereto and the reaction is carried out under cooling with ice or under reflux to obtain an intended compound of formula (I). 
     Process 2 
     A compound of general formula (V), (VI) or (VII) is added to a compound of general formula (III) in a solvent such as methanol, ethanol, isopropanol, butanol, dimethylformamide, dimethylacetamide, diethyl ether, dioxane, dimethyl sulfoxide, tetrahydrofuran or acetonitrile. Then, a sodium or potassium alcoholate such as sodium methylate, sodium ethylate, potassium methylate or potassium ethylate is added thereto and the reaction is carried out under cooling with ice or under reflux to obtain an intended compound of formula (I). 
     Process 3 
     A compound of general formula (V), (VI) or (VII) is added to a compound of general formula (III) in a solvent such as chloroform, dichloromethane, dichloroethane, acetone, methyl ethyl ketone, methanol, ethanol, isopropanol, butanol, dimethylformamide, dimethylacetamide, diethyl ether, dioxane, tetrahydrofuran or dimethyl sulfoxide. Then, a compound such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, triethylamine, diisopropylethylamine, dimethylaminopyridine or pyridine is added thereto and the reaction is carried out at room temperature or under reflux to obtain an intended compound of formula (I). 
     REACTION STEP C 
     Process 1 
     A compound of general formula (II) is reacted with sodium hydride, potassium hydride, calcium hydride or sodium amide in a solvent such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dioxane, diethyl ether, tetrahydrofuran or acetonitrile under cooling with ice or at room temperature. A compound of general formula (VIII), (IX) or (X) is added thereto and the reaction is carried out at room temperature or under reflux to obtain an intended compound of formula (I). 
     Process 2 
     A compound of the general formula (II) is reacted with a sodium or potassium alcoholate such as sodium methylate, sodium ethylate, potassium methylate or potassium ethylate in a solvent such as methanol, ethanol, isopropanol, butanol, dimethylformamide, dimethylacetamide, diethyl ether, dioxane, tetrahydrofuran or acetonitrile under cooling with ice or at room temperature. A compound of general formula (VIII), (IX) or (X) is added to the reaction product and the reaction is carried out at room temperature or under reflux to obtain an intended compound of formula (I). 
     Process 3 
     A base such as potassium carbonate, sodium carbonate, potassium hydroxide, sodium hydroxide, triethylamine, diisopropylethylamine, pyridine or dimethylaminopyridine and a compound of general formula (VIII), (IX) or (X) are added to a compound of general formula (II) in a solvent such as dimethylformamide, dimethylacetamide, dimethyl sulfoxide, diethyl ether, dioxane, tetrahydrofuran, acetonitrile, acetone, methyl ethyl ketone, methanol, ethanol, isopropanol or butanol and the reaction is carried out at room temperature or under reflux to obtain an intended compound of formula (I). 
     Examples of the compounds provided by the present invention will be given below. These examples do not limit the scope of the present invention, but rather, are intended to facilitate an understanding of the invention. The compounds listed below are in their free forms. The compounds of formula (I) of the present invention include all of their stereoisomers and optical isomers which might be formed when they have asymmetric carbon atom(s) the number of which varies depending on the substituents. 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2-methyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2-methyl-1&#39;-[3-(4-hydroxy-4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-fluoro-2-methyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-fluoro-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[4-(4-phenylpiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dipropyl-6-fluoro-1-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[3-(4-hydroxy-4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,6-dimethyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-methoxy-2-methyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-methoxy-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dibutyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dibutyl-1&#39;-[3-(4-hydroxy-4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6,8-dichloro-2,2-dimethyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6,8-dichloro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6,8-dichloro-1&#39;-[4-(4-hydroxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6,8-dichloro-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     8-chloro-2,2-dimethyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-diethyl-6-fluoro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-diethyl-6-fluoro-1&#39;-[4-(4-hydroxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-fluoro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-fluoro-1&#39;-[4-(4-hydroxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-fluoro-1&#39;-[5-(4-hydroxypiperidino)pentyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-methoxy-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-methoxy-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-methyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-methyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-methyl-1&#39;-[3-(4-methoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-methoxy-1&#39;-[3-(4-acetoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4-propoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dipropyl-6-fluoro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dipentyl-6-fluoro-1&#39;-[4-(4-hydroxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4- methoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-fluoro-1&#39;-[3-(4-methoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[3-(4-ethoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[4-(4-hydroxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-bromo-2,2-dimethyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-bromo-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-bromo-2,2-dimethyl-1&#39;-[2-(4-hydroxypiperidino)ethyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-bromo-2,2-diethyl-1&#39;-[4-(4-hydroxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-7-methoxy-8-methyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     7-methoxy-8-methyl-1&#39;-[3-(4-hydroxy-4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dihexyl-6-fluoro-1&#39;-[3-(4-acetoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4-hydroxy-4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4-acetoxy-4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     8-chloro-1&#39;-[3-(4-hydroxypiperidino]propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     8-chloro-1&#39;-[3-(4-acetoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-{3-[4-(2-chlorobenzyloxy)piperidinol]propyl}spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-{3-[4-(4-chlorobenzyloxy)piperidino]propyl}spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[2-(4-hydroxypiperidino)ethyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[2-(4-acetoxypiperidino)ethyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-1&#39;-[4-(4-acetoxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-dichloro-2,2-diethyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-diethyl-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-diethyl-1&#39;-[2-(4-hydroxypiperidino)ethyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[4-(4-hydroxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[4-(4-acetoxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[4-(4-phenylpiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4-oxopiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dibutyl-6-fluoro-1&#39;-[3-(4-oxopiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4-acetoxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     1&#39;-[3-(4-hydroxy-4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-(3-piperidinopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     cyclohexane&lt;spiro-2&gt;-6-chloro-1&#39;[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     cyclopentane&lt;spiro-2&gt;-6-fluoro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4-phenylpiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(4-ethylenedioxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[3-(3-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[6-(4-hydroxypiperidino)hexyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[4-(4-acetoxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[5-(4-hydroxypiperidino)pentyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[6-(4-hydroxypiperidino)hexyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dimethyl-1&#39;-[7-(4-hydroxypiperidino)heptyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-dibutyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     cyclohexane&lt;spiro-2&gt;-6-methoxy-1&#39;-[3-(4-hydroxypiperidinol)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2-methyl-1&#39;-(2-dimethylaminoethyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2-methyl-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-fluoro-2-methyl-1&#39;-(2-methylaminoethyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2-methyl-1&#39;-(2-diethylaminoethyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-chloro-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2-ethyl-6-chloro-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     cyclohexane&lt;spiro-2&gt;-6-chloro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-bromo-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     cyclopentane&lt;spiro-2&gt;-6-chloro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-8-nitro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-fluoro-2-methyl-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-(2-diethylaminoethyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-(2-diisopropylaminoethyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-(3-diethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2&#39;-dimethyl-6-fluoro-1&#39;-(3-n-propylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2,2-di-n-propyl-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-chloro-1&#39;-(4-dimethylaminobutyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-chloro-1&#39;-(5-dimethylaminopentyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-chloro-1&#39;-(6-dimethylaminohexyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2&#39;-dimethyl-6-chloro-1&#39;-(7-dimethylaminoheptyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2-methyl-1&#39;-(6-dimethylaminohexyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-(6-dimethylaminohexyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-(4-dimethylaminobutyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-(3-morpholinopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-[(3-hydroxyamino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-{3-[bis(2-hydroxyethyl)amino]propyl}spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     8-chloro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,5-dimethyl-6-fluoro-1&#39;-(2-dimethylaminoethyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     1-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-{3-[2-(3,4-dimethoxyphenyl)ethylmethylamino]propyl}spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-fluoro-1&#39;-{3-[4-(2-methoxyphenyl)piperazinol]propyl}spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-bromo-1&#39;-(6-dimethylaminohexyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-bromo-1&#39;-(4-dimethylaminobutyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-methyl-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-methoxy-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-dimethyl-6-nitro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-di-n-butyl-6-chloro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     2,2-di-n-hexyl-6-chloro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione, 
     6-chloro-2-n-hexyl-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione. 
     2.2-dimethyl-6-nitro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5-dione, 
     2.2-dimethyl-6.8-dinitro-1&#39;-[3-(4-hydroxypiperridino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione 
     2.2-dimethyl-6-fluoromethyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione 
     2.2-dimethyl-6-chloro-1&#39;[3-(4-octanoyloxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione 
     2.2-dimethyl-β,β,β-trifluorolthoxy-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione 
     2.2-dimethyl-6-chroro-1&#39;-(3-benzylaminopropyl)-spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione 
     2.2-dimethyl-6-chroro-1&#39;-[3-(4-methylpiperidino)propyl]-spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione 
     The compounds of the formula (1) of the present invention and their salts are new compounds which have not been disclosed in literature as far as we are aware yet. They have an excellent antiarrhythmic activity with only a low toxicity. They are useful as antiarrhythmic agents for the treatment of arrhythmia of various types. 
     The compounds of the present invention have a chemical structural formula (I) shown above which is utterly different from those of known antiarrhythmic agents and is quite unique. 
     The compounds of the present invention have a characteristic feature that they have no cardioinhibitory effect. This is quite advantageous when they are used as the antiarrhythmic agents. 
     The antiarrhythmic activity of the compounds of the present invention lasts for a long time. The compounds have only a low toxicity and a wide safety margin (high therapeutic index). Therefore, the compounds are useful as preferred antiarrhythmic agents. 
     The results of the following pharmacological tests will prove the effects of the compounds of the present invention. 
     EXPERIMENTAL EXAMPLE 
     (1) Chloroform-induced arrhythmia (mice): 
     Ventricular arrhythmia was caused experimentally in mice by the following method. 
     The mice were placed in a device filled with chloroform gas. After expiring, the ventricular pulse was counted from a record of an electrocardiogram. The antiarrhythmic activity of the test compound was determined based on its effect of relieving tachycardia. The lethal dose, toxic dose and minimum effective dose of each compound were determined. The compounds were tested by administration by two routes, i.e. peroral and intravenous injection. Relative peroral effects of them were inferred from the results. The lasting time (duration) was inferred from changes in the medicinal effects observed when the time interval between the administration of the compound and the treatment of the mice with chloroform was varied. Table 1 shows the results (effective dose on arrhythmia and lethal dose) of experiments wherein a test compound was given to mice perorally one hour before the treatment with chloroform. As comparative standard medicines, quinidine, disopyramide and phenytoin were employed. This method is taught in the publication, J. Pharmacol. Exp. Ther. 160,22 (1968), by J. W. Lawson. 
     
                                           TABLE 1                                 
__________________________________________________________________________
 ##STR6##                                                                 
Test compound              Effective dose                                 
                                   Lethal dose                            
X.sup.1                                                                   
   X.sup.2                                                                
      R.sup.1                                                             
         R.sup.2                                                          
            n Z            (mg/kg) (mg/kg)                                
__________________________________________________________________________
6-F                                                                       
   H  CH.sub.3                                                            
         CH.sub.3                                                         
            2                                                             
               ##STR7##    12.5    200                                    
6-F                                                                       
   H  CH.sub.3                                                            
         CH.sub.3                                                         
            2                                                             
               ##STR8##    25      200                                    
6-F                                                                       
   H  CH.sub.3                                                            
         CH.sub.3                                                         
            2                                                             
               ##STR9##    50      400                                    
6-Cl                                                                      
   H  H  CH.sub.3                                                         
            3                                                             
               ##STR10##   12.5     50                                    
6-Cl                                                                      
   H  C.sub.2 H.sub.5                                                     
         C.sub.2 H.sub.5                                                  
            3                                                             
               ##STR11##   25      400                                    
6-Cl                                                                      
   H  CH.sub.3                                                            
         CH.sub.3                                                         
            3                                                             
               ##STR12##   25      400                                    
6-F                                                                       
   H  CH.sub.3                                                            
         CH.sub.3                                                         
            3                                                             
               ##STR13##   25      400                                    
6-Cl                                                                      
   8-Cl                                                                   
      CH.sub.3                                                            
         CH.sub.3                                                         
            3                                                             
               ##STR14##   12.5    400                                    
6-F                                                                       
   H  CH.sub.3                                                            
         CH.sub.3                                                         
            3                                                             
               ##STR15##   50      200                                    
6-F                                                                       
   H  C.sub.2 H.sub.5                                                     
         C.sub.2 H.sub.5                                                  
            3                                                             
               ##STR16##   25      400                                    
6-F                                                                       
   H  CH.sub.3                                                            
         CH.sub.3                                                         
            3                                                             
               ##STR17##   25      400                                    
Quinidine sulfonate        200     800                                    
Disopyramide phosphate     50      600                                    
Phenytoin sodium           100     &gt; 800                                  
__________________________________________________________________________
 
    
     It is apparent from Table 1 that the antiarrhythmic activities of the compounds of the present invention are stronger than those of the comparative ones and the safety margin (ratio of the lethal dose to the effective dose) of the former is larger than that of the latter. 
     The effects of these compounds lasted for 3 to 6 h after the peroral administration. 
     (2) Aconitine-induced arrhythmia (mice): 
     A toxic dose of aconitine was administered to mice and a ventricular extrasystole caused thereby was examined. When 0.1 mg/kg of aconitine is given to mice by intraabdominal injection, the ventricular tachycardia is caused in 20 min in general. In this experiment, a test compound in given doses as in the above experiment (1) was given to the mice perorally and, after a given time, aconitine was administered by injection. The occurrence of arrhythmia was examined and the ventricular extrasystole was counted from the electrocardiogram to determine the antiarrhythmic activity. Table 2 shows the results of the tests in which a test compound or a comparative standard medicine (quinidine or disopyramide) was administered perorally one hour before the intraabdominal injection of 0.1 mg/kg of aconitine. This method is taught in the publication, IUPHAR 9th International Congress of Pharmacology (Abstacts 454p) by T. Igarashi. 
     
                       TABLE 2                                                     
______________________________________                                    
 ##STR18##                    (A)                                         
 ##STR19##                    (B)                                         
                  Effective dose                                          
Test compound     (mg/kg)                                                 
______________________________________                                    
general formula (A)                                                       
n = 2             80                                                      
n = 3             5                                                       
n = 4             10                                                      
n = 5             40                                                      
n = 6             40                                                      
n =  7            40                                                      
general formula (B)                                                       
X.sup.1 = 6-F, X.sup.2 = H                                                
                  5                                                       
X.sup.1 = 6-Cl, X.sup.2 = H                                               
                  5                                                       
X.sup.1 = 6-Br, X.sup.2 = H                                               
                  10                                                      
X.sup.1 = 6-CH.sub.3, X.sup.2 = H                                         
                  &gt;80                                                     
X.sup.1 = 6-Cl, X.sup.2 = 8-Cl                                            
                  10                                                      
Quinidine sulfate 80                                                      
Disopyramide phosphate                                                    
                  40                                                      
______________________________________                                    
 
    
     The effective dose shown in Table 2 is that required for treating the aconitine-induced ventricular tachycardia to realize a ratio of normal sinus rhythm to ventricular pulse of about 1:1. Many of the test compounds exhibited their effects in an amount smaller than that of quinidine or disopyramide. 
     When the compounds were used in an amount larger than the effective amount shown in Table 2, aconitine-induced ventricular arrhythmia was normalized to recover the perfect sinus rhythm. This effect lasted even 6 hours after the peroral administration. 
     (3) Acute toxicity (rats): 
     The acute toxicity tests on rats (peroral administration) were effected using typical compounds of the present invention, i.e. 6-chloro-2,2-dimethyl-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione (compound 1) and 2,2-dimethyl-6-fluoro-1&#39;-[3-(4-hydroxypiperidino)propyl]-spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione (compound 2). The results are shown in Table 3. 
     
                       TABLE 3                                                     
______________________________________                                    
                LD.sub.50                                                 
                     mg/kg                                                
______________________________________                                    
Compound 1        ♂ 930                                              
                  ♀                                                
                         858                                              
Compound 2        ♂ 860                                              
                  ♀                                                
                         780                                              
______________________________________                                    
 
    
     The results of the above-mentioned tests proved that the compounds of the present invention have an excellent, long-lasting antiarrhythmic activity, low toxicity and wide safety margin (high therapeutic index) and they can be used as preferred antiarrhythmic agents. 
     The antiarrhythmic mechanism of the compounds of the present invention was examined on the basis of the effects on resting potential and action potential of extracted myocardia of guinea pigs and swine by a microelectrode method. As a result, it was found that the compounds of the present invention reduce the rate of the action potential rise, although they exert no influence on the resting potential. Particularly when the electric stimulation was strong, the action potential-inhibiting effect was strong. This property is common to antiarrhythmic agents of Class 2 (quinidine, disopyramide). This fact indicates that the mechanism and diseases for which the compounds of the present invention are efficacious (i.e. supraventricular and ventricular arrhythmia) are the same as those of the antiarrhythmic agents of Class 2. 
     One of the pharmacological features of the compounds of the present invention is that they do not substantially inhibit the contraction of the myocardia. This property is quite preferred when they are used as antiarrhythmic agents. More particularly, although quinidine and disopyramide reduce the contraction power of the myocardia in a dose several times as much as that required for realizing the antiarrhythmic effects, the compounds of the present invention exhibit no influence on the contraction power of the myocardia even when administered in an amount 10 times as much as the effective dose for the antiarrhythmia treatment. 
     The compounds of the present invention are effective for the treatment and prevention of various types of arrhythmia such as ventricular arrhythmia and atrial (supraventricular) arrhythmia. 
     In using the compounds of the present invention as antiarrhythmic agents, they are administered perorally or parenterally (intramuscular, subcutaneous or intravenous administration). The dosage varies depending on the patient, symptoms and age and is not particularly limited. However, generally, the dosage is about 1 to 1,000 mg/day, preferably about 100 to 300 mg/day, for adult human beings. 
     The compounds of the present invention can be formulated into tablets, granules, powders, capsules, injections and suppositories by any methods generally employed in the pharmaceutical field. 
     In the preparation of peroral solid products, an excipient and, if necessary, binder, disintegrator, lubricant, colorant and corrigent are added to the active ingredient and the mixture is shaped into tablets, coated tablets, granules, powders or capsules by a conventional method. 
     The excipients include, for example, lactose, corn starch, white sugar, glucose, sorbitol and crystalline cellulose. The binders include, for example, polyvinyl alcohol, polyvinyl ether, ethylcellulose, methylcellulose, gum arabic, tragacanth, gelatin, shellac, hydroxypropylcellulose, hydroxypropylstarch and polyvinylpyrrolidone. The disintegrators include, for example, starch, agar, gelatin powder, crystalline cellulose, calcium carbonate, sodium hydrogencarbonate, calcium citrate, dextrin and pectin. The lubricants include, for example, magnesium stearate, talc, polyethylene glycol, silica and hardened vegetable oils. The colorants include, for example, those allowed for medicines. The corrigents include, for example, cocoa powder, menthol, aromatic powder, peppermint oil, borneol and cinnamon powder. These tablets and granules can be coated with sugar, gelatin or the like, if necessary. 
     In the formulation of the injections, necessary components such as a pH-adjusting agent, buffering agent, stabilizer, solubilizer and preservative are added to the active ingredient and the mixture is formulated into subcutaneous, intramuscular or intravenous injectable solutions by a conventional method. 
     The following examples will further illustrate the present invention, but these examples by no means limit the scope of the invention. 
    
    
     EXAMPLE 1 
     2,2-Dimethyl-6-fluoro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione 
     (1) 2,2-Dimethyl-6-fluoro-1&#39;-(3-bromopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione: 
     1.0 g (25 mM) of sodium hydride (60% suspension in mineral oil) was added to a solution of 6.6 g (25 mM) of 2,2-dimethyl-6-fluoro-spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione and a solution of 10.1 g (50 mM) of 1,3-dibromopropane in 70 ml of dimethylformamide at 15° to 30° C. The mixture was stirred at room temperature for 5 h. The reaction liquid was poured into ice/water. After extraction with ethyl acetate, the resulting ethyl acetate layer was washed with water and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure. 12.7 g of a residue was purified according to silica gel column chromatography (developer: dichloromethane/ethanol) to obtain 6.95 g (yield: 72.2%) of the intended compound. 
     melting point: 190° to 192° C. 
     
         ______________________________________                                    
elementary analysis for C.sub.16 H.sub.18 BrFN.sub.2 O.sub.3 :            
           C         H      N                                             
______________________________________                                    
calculated (%)                                                            
             49.87       4.71   7.27                                      
found (%)    49.63       4.59   7.15                                      
______________________________________                                    
 
    
     NMR (CDCl 3 ): 1.32 (3H, s), 1.50 (3H, s), 2.02 (1H, d, J=16 Hz), 2.24 (2H, q, J=8 Hz), 2.60 (1H, d, J=16Hz), 3.40 (2H, t, J=8 Hz), 3.74 (2H, t, J=8 Hz), 6.36 (1H, s), 6.45-7.10 (3H, m) 
     (2) 2,2-Dimethyl-6-fluoro-1&#39;-[3-(4-hydroxypiperidino)propyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione: 
     6.0 g (15.6 mM) of the bromine compound obtained in the above step (1) of Example (1), 3.15 g (31.2 mM) of 4-hydroxypiperidine, 4.31 g (31.2 mM) of potassium carbonate and a solution of a small amount of potassium iodide in 70 ml of dimethylformamide were reacted together at 80° C. for 5 h. The reaction liquid was poured into water and extracted with ethyl acetate. The resulting ethyl acetate layer was washed with water and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure and the residue was recrystallized from ethanol/ethyl acetate to obtain 5.85 g (yield: 92.6%) of the intended compound. The product was then converted into its hydrochloride salt by a conventional method. 
     melting point: 211° to 213° C. (free form): 195° to 197° C. (hydrochloride). 
     
         ______________________________________                                    
elementary analysis for C.sub.21 H.sub.38 FN.sub.3 O.sub.4 :              
           C         H      N                                             
______________________________________                                    
calculated (%)                                                            
             62.20       6.96   10.36                                     
found (%)    61.92       7.01   10.25                                     
______________________________________                                    
 
    
     NMR (CDOD)δ: 1.32 (3H, s), 1.52 (3H, s), 1.60-3.00 (14H, m), 3.62 (2H, t, J=8 Hz), 3.45-3.80 (1H, m), 6.50-7.10 (3H, m) 
     EXAMPLE 2 
     8-Chloro-1&#39;-(3-dimethylaminopropyl)spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione 
     240 mg (6 mM) of sodium hydride (60% suspension in mineral oil) was added to a solution of 1.52 g (6 mM) of 8-chloro-spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione in 30 ml of dimethylformamide at 5° C. The mixture was stirred for 10 min. Then, a solution of 802 mg (6.6 mM) of 3-dimethylaminopropyl chloride in 3 ml of dimethylformamide was added dropwise thereto at room temperature over 10 min. The reaction was carried out at 80° to 90° C. for 5 h. The reaction liquid was poured into ice/water and extracted with ethyl acetate. The resulting ethyl acetate layer was washed with water and then dried over magnesium sulfate. The solvent was distilled under reduced pressure. 2.65 g of a residue was purified according to silica gel column chromatography (developer: dichlorometane/ethanol) to obtain 1.60 g (yield: 79.0%) of the intended compound. The product was then converted into its hydrochloride by a conventional method. 
     melting point: 158° to 159° C. (free form); 202° to 204° C. (HCl salt). 
     
         ______________________________________                                    
elementary analysis for C.sub.16 H.sub.20 ClN.sub.3 O.sub.3 C             
           C         H      N                                             
______________________________________                                    
calculated (%):                                                           
             56.89       5.97   12.44                                     
found (%)    56.84       5.93   12.39                                     
______________________________________                                    
 
    
     NMR (CDCl 3 )δ: 1.60-1.96 (2H, m), 2.14 (6H, s), 2.00-2.44 (4H, m), 3.58 (2H, t, J=8 Hz), 4.18-4.44 (1H, m), 4.64-4.98 (1H, m), 6.16 (1H, s), 6.60-7.02 (2H, m), 7.16-7.36 (1H, m) 
     EXAMPLES 3 to 84 
     (1) Intermediates shown in the following Tables 4 and 5 were obtained in the same manner as in Example 1-(1). 
     (2) The intended compounds shown in the following Tables 6, 7, 8 and 9 were obtained in the same way as in Example 1-(2) or Example 2. 
     
                       TABLE 4                                                     
______________________________________                                    
 ##STR20##                                                                
                      Elementary                                          
                      analysis (upper                                     
                      column: cal-                                        
                      culated, lower                                      
                      column: found)                                      
                               m.p.   C    H    N                         
X.sup.1                                                                   
       X.sup.2 R.sup.1                                                    
                      R.sup.2                                             
                           n   (°C.)                               
                                      (%)  (%)  (%)                       
______________________________________                                    
6-F    H       CH.sub.3                                                   
                      CH.sub.3                                            
                           4   144-146                                    
                                      51.14                               
                                           5.05 7.02                      
                                      51.38                               
                                           5.16 7.01                      
6-Cl   H       CH.sub.3                                                   
                      CH.sub.3                                            
                           3   191-194                                    
                                      47.84                               
                                           4.52 6.97                      
                                      48.10                               
                                           4.53 7.02                      
7-OCH.sub.3                                                               
       8-CH.sub.3                                                         
               CH.sub.3                                                   
                      CH.sub.3                                            
                           3   211-213                                    
                                      52.56                               
                                           5.64 6.81                      
                                      52.27                               
                                           5.60 6.54                      
6-Cl   H       H      H    3   181-183                                    
                                      45.01                               
                                           3.78 7.50                      
                                      45.26                               
                                           3.80 7.62                      
6-Cl   H       C.sub.2 H.sub.5                                            
                      C.sub.2 H.sub.5                                     
                           3   172-174                                    
                                      50.31                               
                                           5.16 6.52                      
                                      50.47                               
                                           5.15 6.45                      
6-F    H       CH.sub.3                                                   
                      CH.sub.3                                            
                           2   201-203                                    
                                      48.54                               
                                           4.35 7.55                      
                                      48.73                               
                                           4.37 7.51                      
6-F    H       CH.sub.3                                                   
                      CH.sub.3                                            
                           6   97.5-99.5                                  
                                      53.40                               
                                           5.66 6.55                      
                                      53.42                               
                                           5.67 6.52                      
6-Cl   H       CH.sub.3                                                   
                      CH.sub.3                                            
                           4   183-186                                    
                                      49.12                               
                                           4.85 6.74                      
                                      49.37                               
                                           4.89 6.57                      
6-Cl   H       CH.sub.3                                                   
                      CH.sub.3                                            
                           5   181-184                                    
                                      50.31                               
                                           5.16 6.52                      
                                      50.19                               
                                           5.17 6.48                      
6-Cl   H       CH.sub.3                                                   
                      CH.sub.3                                            
                           6   120.5-122                                  
                                      51.42                               
                                           5.45 6.31                      
                                      51.37                               
                                           5.37 6.39                      
6-Cl   H       CH.sub.3                                                   
                      CH.sub.3                                            
                           7   125-126                                    
                                      52.47                               
                                           5.73 6.12                      
                                      52.57                               
                                           5.81 6.07                      
6-Cl   H       C.sub.2 H.sub.5                                            
                      C.sub.2 H.sub.5                                     
                           3   171-173                                    
                                      50.31                               
                                           5.16 6.52                      
                                      50.27                               
                                           5.08 6.51                      
______________________________________                                    
 
    
     
                       TABLE 5                                                     
______________________________________                                    
 ##STR21##                                                                
                   Elementary analysis                                    
                   (upper column:                                         
                   calculated, lower                                      
                   column: found)                                         
X.sup.1                                                                   
     X.sup.2                                                              
           R.sup.1                                                        
                  R.sup.2                                                 
                       n   m.p. (°C.)                              
                                   C(%)  H (%) N (%)                      
______________________________________                                    
6-Cl H     CH.sub.3                                                       
                  H    3   146-148 52.50 4.70  8.16                       
                                   52.65 4.77  8.08                       
6-F  H     CH.sub.3                                                       
                  H    3   143-145 55.14 4.94  8.57                       
                                   55.32 4.98  8.43                       
6-Cl H     CH.sub.3                                                       
                  CH.sub.3                                                
                       3   204-206 53.80 5.08  7.84                       
                                   53.93 5.12  7.73                       
______________________________________                                    
 
    
     
                                           TABLE 6                                 
__________________________________________________________________________
 ##STR22##                                                                
                                                   Elementary analysis    
                                                   (upper column:         
                                                   calculated, lower      
Exam-                                       Molecular                     
                                                   column: found)         
ple X.sup.1                                                               
       X.sup.2                                                            
           R.sup.1                                                        
               R.sup.2                                                    
                   n R.sup.3                                              
                           R.sup.4    m.p. (°C.)                   
                                            formula                       
                                                   C (%)                  
                                                       H                  
                                                           N              
__________________________________________________________________________
                                                           (%)            
 3  6-Cl                                                                  
       H   H   CH.sub.3                                                   
                   2 CH.sub.3                                             
                           CH.sub.3   300   C.sub.16 H.sub.20 ClN.sub.3   
                                                   51.34                  
                                                       5.65               
                                                           11.23          
                                            O.sub.3.HCl                   
                                                   51.52                  
                                                       5.77               
                                                           11.35          
 4  6-Cl                                                                  
       H   H   CH.sub.3                                                   
                   3 CH.sub.3                                             
                           CH.sub.3   300   C.sub.17 H.sub.22 ClN.sub.3   
                                                   52.58                  
                                                       5.97               
                                                           10.82          
                                            O.sub.3.HCl                   
                                                   52.37                  
                                                       5.98               
                                                           10.75          
 5  6-F                                                                   
       H   H   CH.sub.3                                                   
                   2 CH.sub.3                                             
                           CH.sub.3   300   C.sub.16 H.sub.20 FN.sub.3    
                                                   51.34                  
                                                       5.65               
                                                           11.23          
                                            O.sub.3.HCl                   
                                                   51.57                  
                                                       5.56               
                                                           11.34          
 6  6-Cl                                                                  
       H   H   CH.sub.3                                                   
                   2 C.sub.2 H.sub.5                                      
                           C.sub.2 H.sub.5                                
                                      270-272                             
                                            C.sub.18 H.sub.24 ClN.sub.3   
                                                   53.73                  
                                                       6.26               
                                                           10.44          
                                            O.sub.3.HCl                   
                                                   53.88                  
                                                       6.13               
                                                           10.45          
 7  6-Cl                                                                  
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 CH.sub.3                                             
                           CH.sub.3   269-270                             
                                            C.sub.18 H.sub.24 ClN.sub.3   
                                                   53.73                  
                                                       6.26               
                                                           10.44          
                                            O.sub.3.HCl                   
                                                   53.84                  
                                                       6.19               
                                                           10.35          
 8  6-Cl                                                                  
       H   H   C.sub.2 H.sub.5                                            
                   3 CH.sub.3                                             
                           CH.sub.3   262-263                             
                                            C.sub.18 H.sub.24 Cl          
                                                   53.73                  
                                                       6.26               
                                                           10.44          
                                            N.sub.3 O.sub.3.HCl           
                                                   53.89                  
                                                       6.20               
                                                           10.47          
 9  6-Cl                                                                  
       H                                                                  
            ##STR23##                                                     
                   3 CH.sub.3                                             
                           CH.sub.3   230-241                             
                                            C.sub.21 H.sub.28 ClN.sub.3   
                                            O.sub.3.HCl                   
                                                   57.01 58.95            
                                                       6.38 6.27          
                                                            9.50 9.61     
10  6-Br                                                                  
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 CH.sub.3                                             
                           CH.sub.3   277-279                             
                                            C.sub.18 H.sub.24 BrN.sub.3   
                                                   48.50                  
                                                       5.65               
                                                            9.43          
                                            O.sub.3.HCl                   
                                                   48.29                  
                                                       5.73               
                                                            9.21          
11  6-Cl                                                                  
       H                                                                  
            ##STR24##                                                     
                   3 CH.sub.3                                             
                           CH.sub.3   waxy  C.sub.20 H.sub.26 Cl N.sub.3  
                                            O.sub.3.HCl                   
                                                   56.08 56.02            
                                                       6.12 6.17          
                                                            9.81 9.75     
12  6-F                                                                   
       8-NO.sub.2                                                         
           CH.sub.3                                                       
               CH.sub.3                                                   
                   3  CH.sub.3                                            
                           CH.sub.3   274-276                             
                                            C.sub.18 H.sub.23 FN.sub.4    
                                                   52.11                  
                                                       5.83               
                                                           13.51          
                                            O.sub.5.HCl                   
                                                   52.24                  
                                                       5.75               
                                                           13.59          
13  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 CH.sub.3                                             
                           CH.sub.3   146-169                             
                                            C.sub.18 H.sub.24 F           
                                                   56.17                  
                                                       6.55               
                                                           10.92          
                                            N.sub.3 O.sub.3.HCl           
                                                   56.23                  
                                                       6.51               
                                                           10.75          
14  6-Cl                                                                  
       H   C.sub.2 H.sub.5                                                
               C.sub.2 H.sub.5                                            
                   3 CH.sub.3                                             
                           CH.sub.3   203-205                             
                                            C.sub.20 H.sub.28 Cl          
                                                   60.98                  
                                                       7.16               
                                                           10.67          
                                            N.sub.3 O.sub.3.HCl           
                                                   60.73                  
                                                       7.08               
                                                           10.62          
15  6-F                                                                   
       H   H   CH.sub.3                                                   
                   3 CH.sub.3                                             
                           CH.sub.3   waxy  C.sub.17 H.sub.22 F           
                                                   54.91                  
                                                       6.23               
                                                           11.30          
                                            N.sub.3 O.sub.3.HCl           
                                                   54.78                  
                                                       6.15               
                                                           11.21          
16  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   2 C.sub.2 H.sub.5                                      
                           C.sub.2 H.sub.5                                
                                      154-156                             
                                            C.sub.19 H.sub.20 F           
                                                   62.79                  
                                                       7.21               
                                                           11.56          
                                            N.sub.3 O.sub.3               
                                                   62.74                  
                                                       7.28               
                                                           11.49          
17  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   2 C.sub.2 H.sub.5                                      
                           C.sub.2 H.sub.5                                
                                      206-208                             
                                            C.sub.19 H.sub.20 F           
                                                   57.07                  
                                                       6.81               
                                                           10.51          
                                            N.sub.3 O.sub.3.HCl           
                                                   56.98                  
                                                       6.95               
                                                           10.35          
18  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   2 i-C.sub.3 H.sub.7                                    
                           i-C.sub.3 H.sub.7                              
                                      122-124                             
                                            C.sub.21 H.sub.30 F           
                                                   64.43                  
                                                       7.72               
                                                           10.73          
                                            N.sub.3 O.sub.3               
                                                   64.43                  
                                                       7.82               
                                                           10.67          
19  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   2 i-C.sub.3 H.sub.7                                    
                           i-C.sub.3 H.sub.7                              
                                      230-233                             
                                            C.sub.21 H.sub.30 F           
                                                   58.94                  
                                                       7.30               
                                                            9.82          
                                            N.sub.3 O.sub.3.HCl           
                                                   58.75                  
                                                       7.25               
                                                            9.60          
20  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 C.sub.2 H.sub.5                                      
                           C.sub.2 H.sub.5                                
                                       99-100                             
                                            C.sub.20 H.sub.28 F           
                                                   63.64                  
                                                       7.48               
                                                           11.13          
                                            N.sub.3 O.sub.3               
                                                   63.54                  
                                                       7.54               
                                                           11.02          
21  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 C.sub.2 H.sub.5                                      
                           C.sub.2 H.sub.5                                
                                      232-235                             
                                            C.sub.20 H.sub.28 F           
                                                   58.03                  
                                                       6.82               
                                                           10.15          
                                            N.sub.3 O.sub.3.HCl           
                                                   57.82                  
                                                       7.11               
                                                            9.95          
22  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 n-C.sub.3 H.sub.7                                    
                           n-C.sub.3 H.sub.7                              
                                      235-237                             
                                            C.sub.22 H.sub.32 F           
                                                   59.79                  
                                                       7.30               
                                                            9.51          
                                            N.sub.3 O.sub.3.HCl           
                                                   59.57                  
                                                       7.25               
                                                            9.27          
23  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3                                                      
                          ##STR25##   235-238                             
                                            C.sub.20 H.sub.26 F N.sub.3   
                                            O.sub.4.HCl                   
                                                   56.14 55.94            
                                                       6.13 6.40          
                                                            9.82 9.54     
24  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 H     (CH.sub.2).sub.3 OH                            
                                      138-139                             
                                            C.sub.19 H.sub.26 F           
                                                   60.14                  
                                                       6.91               
                                                           11.07          
                                            N.sub.3 O.sub.4               
                                                   59.87                  
                                                       6.85               
                                                           10.91          
25  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 H     (CH.sub.2).sub.3 OH                            
                                      187-189                             
                                            C.sub. 19 H.sub.26 F          
                                                   54.61                  
                                                       6.75               
                                                           10.05          
                                            N.sub.3 O.sub.4.HCl           
                                                   54.41                  
                                                       6.52               
                                                            9.82          
26  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 (CH.sub.2).sub.3 OH                                  
                           (CH.sub.2).sub.3 OH                            
                                      198-200                             
                                            C.sub.20 H.sub.30 FN.sub.3    
                                                   55.61                  
                                                       7.00               
                                                            9.73          
                                            O.sub.5.HCl                   
                                                   55.41                  
                                                       6.78               
                                                            9.65          
27  6-Cl                                                                  
       H   H   H   3 CH.sub.3                                             
                           CH.sub.3   131-133                             
                                            C.sub.16 H.sub.20 Cl          
                                                   56.89                  
                                                       5.97               
                                                           12.44          
                                            N.sub.3 O.sub.3               
                                                   56.78                  
                                                       5.82               
                                                           12.65          
28  6-Cl                                                                  
       H   H   H   3 CH.sub.3                                             
                           CH.sub.3   279-281                             
                                            C.sub.16 H.sub.20 Cl          
                                                   51.35                  
                                                       5.66               
                                                           11.23          
                                            N.sub.3 O.sub.3.HCl           
                                                   51.33                  
                                                       5.64               
                                                           11.17          
29  8-Cl                                                                  
       H   H   H   3 CH.sub.3                                             
                           CH.sub.3   158-159                             
                                            C.sub.16 H.sub.20 Cl          
                                                   56.89                  
                                                       5.97               
                                                           12.44          
                                            N.sub.3 O.sub.3               
                                                   56.84                  
                                                       5.93               
                                                           12.39          
30  8-Cl                                                                  
       H   H   H   3 CH.sub.3                                             
                           CH.sub.3   202-203                             
                                            C.sub.16 H.sub.20 Cl          
                                                   51.35                  
                                                       5.66               
                                                           11.23          
                                            N.sub.3 O.sub.3.HCl           
                                                   51.33                  
                                                       5.57               
                                                           11.37          
31  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   2 CH.sub.3                                             
                           CH.sub.3   234-235                             
                                            C.sub.17 H.sub.22 FN.sub.3    
                                                   54.91                  
                                                       6.23               
                                                           11.30          
                                            O.sub.3.HCl                   
                                                   54.75                  
                                                       6.11               
                                                           11.21          
32  H  H   H   H   3 CH.sub.3                                             
                           CH.sub.3   118-120                             
                                            C.sub.16 H.sub.21 N.sub.3     
                                                   63.35                  
                                                       6.98               
                                                           13.85          
                                            O.sub.3                       
                                                   63.31                  
                                                       6.91               
                                                           13.81          
33  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 CH.sub.3                                             
                            ##STR26## waxy  C.sub.27 H.sub.24 F N.sub.3   
                                            O.sub.3.HCl                   
                                                   60.49 60.51            
                                                       6.39 6.27          
                                                            7.84 7.78     
34  6-F                                                                   
       H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3                                                      
                      ##STR27##                                           
                            ##STR28## 193-197                             
                                            C.sub.27 H.sub.33 F N.sub.4   
                                            O.sub.4.HCl                   
                                                   60.84 60.75            
                                                       6.43  6.35         
                                                           10.51 10.37    
35  H  H   CH.sub.3                                                       
               CH.sub.3                                                   
                   3 CH.sub.3                                             
                           CH.sub.3   135-137                             
                                            C.sub.18 H.sub.25 N.sub.3     
                                                   65.23                  
                                                       7.60               
                                                           12.68          
                                            O.sub.3                       
                                                   65.31                  
                                                       7.61               
                                                           12.70          
36  6-Cl                                                                  
       H   n-C.sub.3 H.sub.7                                              
               n-C.sub.3 H.sub.7                                          
                   3 CH.sub.3                                             
                           CH.sub.3   112-115                             
                                            C.sub.22 H.sub.32 Cl          
                                                   57.64                  
                                                       7.26               
                                                            9.17          
                                            N.sub.3 O.sub.3.HCl           
                                                   57.59                  
                                                       7.31               
                                                            9.25          
__________________________________________________________________________
 
    
     
                                           TABLE 7                                 
__________________________________________________________________________
 ##STR29##                                                                
                                                 Elementary analysis      
                                                 (upper                   
                                                 column: calculated,      
                                                 lower                    
Exam-                                     Molecular                       
                                                 column: found)           
ple X.sup.1                                                               
         X.sup.2                                                          
             R.sup.1                                                      
                R.sup.2                                                   
                   n R.sup.5     R.sup.6                                  
                                     m.p.(°C.)                     
                                          formula                         
                                                 C (%)                    
                                                      H                   
                                                          N               
__________________________________________________________________________
                                                          (%)             
37  6-Cl H   H  CH.sub.3                                                  
                   3                                                      
                      ##STR30##  H   219-221                              
                                          C.sub.26 H.sub.30 Cl N.sub.3    
                                          O.sub.3.HCl                     
                                                 61.29 61.39              
                                                      6.09 6.21           
                                                           8.20 8.30      
38  6-Cl H   H  CH.sub.3                                                  
                   3                                                      
                      ##STR31##  OH  186-188                              
                                          C.sub.26 H.sub.30 Cl N.sub.3    
                                          O.sub.4.HCl                     
                                                 58.97 58.63              
                                                      6.09 5.86           
                                                           7.93 7.93      
39  6-F  H   H  CH.sub.3                                                  
                   3                                                      
                      ##STR32##  H   196-198                              
                                          C.sub.26 H.sub.30 F N.sub.3     
                                          O.sub.3                         
                                                 61.71 61.57              
                                                      6.37 6.38           
                                                           8.30 8.31      
40  6-F  H   H  H  3                                                      
                      ##STR33##  H   175.177                              
                                          C.sub.25 H.sub.28 F N.sub.3     
                                          O.sub.3                         
                                                 62.16 62.39              
                                                      6.26 6.29           
                                                           8.70 8.57      
41  6-Cl H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3                                                      
                      ##STR34##  H   215-217                              
                                          C.sub.27 H.sub.32 Cl N.sub.3    
                                          O.sub.3.HCl                     
                                                 62.54                    
                                                      6.41                
                                                           8.10           
42  6-Cl H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3                                                      
                      ##STR35##  OH  227-229                              
                                          C.sub.27 H.sub.32 Cl N.sub.3    
                                          O.sub. 4.HCl                    
                                                 60.67 60.42              
                                                      6.22 6.18           
                                                           7.86 7.91      
43  6-CH.sub.3                                                            
         H   H  CH.sub.3                                                  
                   3                                                      
                      ##STR36##  H   170-172                              
                                          C.sub.27 H.sub.33 N.sub.3       
                                          O.sub.3 .HCl                    
                                                 66.99 66.79              
                                                      7.08 7.32           
                                                           8.51 8.51      
44  6-OCH.sub.3                                                           
         H   H  CH.sub.3                                                  
                   3                                                      
                      ##STR37##  H   216-219                              
                                          C.sub.27 H.sub.33 N.sub.3       
                                          O.sub.4.HCl                     
                                                 64.85 64.70              
                                                      6.65 6.69           
                                                           8.40 8.34      
45  6-Cl 8-Cl                                                             
             CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OH          H   waxy C.sub.21 H.sub.27 Cl.sub.2      
                                                 51.18                    
                                                      5.52                
                                                           8.53           
                                          N.sub.3 O.sub.4.HCl             
                                                 50.95                    
                                                      5.47                
                                                           8.29           
46  6-F  H   C.sub.2 H.sub.5                                              
                C.sub.2 H.sub.5                                           
                   3 OH          H   waxy C.sub.23 H.sub.32 F             
                                                 58.78                    
                                                      7.08                
                                                           8.94           
                                          N.sub.3 O.sub.4.HCl             
                                                 58.59                    
                                                      7.16                
                                                           8.88           
47  6-F  H   H  H  3 OH          H   204-206                              
                                          C.sub.19 H.sub.24 FN.sub.3      
                                                 60.46                    
                                                      6.40                
                                                          11.13           
                                          O.sub.4                         
                                                 60.19                    
                                                      6.45                
                                                          11.01           
48  6-CH.sub.3                                                            
         H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OH          H   waxy C.sub.22 H.sub.31 N.sub.3       
                                                 60.34                    
                                                      7.37                
                                                           9.59           
                                          O.sub.4.HCl                     
                                                 60.25                    
                                                      7.41                
                                                           9.62           
49  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OH          H   211-213                              
                                          C.sub.21 H.sub.28 F             
                                                 62.20                    
                                                      6.96                
                                                          10.36           
                                          N.sub.3 O.sub.4                 
                                                 61.92                    
                                                      7.01                
                                                          10.25           
50  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OH          H   195-197                              
                                          C.sub.21 H.sub.28 F             
                                                 57.07                    
                                                      6.61                
                                                           9.51           
                                          N.sub.3 O.sub.4.HCl             
                                                 56.77                    
                                                      6.67                
                                                           9.24           
51  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OCH.sub.3   H   207-208                              
                                          C.sub.22 H.sub.30 F             
                                                 57.96                    
                                                      6.63                
                                                           9.22           
                                          N.sub.3 O.sub.4.HCl             
                                                 57.72                    
                                                      6.78                
                                                           9.11           
52  6-Cl H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OH          H   154-156                              
                                          C.sub.21 H.sub.28 Cl            
                                                 59.78                    
                                                      6.69                
                                                           9.96           
                                          N.sub.3 O.sub.4                 
                                                 59.77                    
                                                      6.42                
                                                            9.89          
53  6-Cl H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OH          H   158-160                              
                                          C.sub.21 H.sub.28 Cl            
                                                 55.03                    
                                                      6.38                
                                                           9.17           
                                          N.sub.3 O.sub.4.HCl             
                                                 55.01                    
                                                      6.57                
                                                           9.15           
54  7-OCH.sub.3                                                           
         8-CH.sub.3                                                       
             CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OH          H   156-158                              
                                          C.sub.23 H.sub.33 N.sub.3       
                                                 64.01                    
                                                      7.71                
                                                           9.74           
                                          O.sub.5                         
                                                 63.98                    
                                                      7.59                
                                                           9.80           
55  7-OCH.sub.3                                                           
         8-CH.sub.3                                                       
             CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OH          H   157-159                              
                                          C.sub.23 H.sub.33 N.sub.3       
                                                 59.03                    
                                                      7.32                
                                                           8.99           
                                          O.sub.5.HCl                     
                                                 58.93                    
                                                      7.04                
                                                           8.85           
56  6-Cl H   H  H  3 OH          H   219-221                              
                                          C.sub.19 H.sub.24 Cl            
                                                 57.94                    
                                                      6.14                
                                                          10.67           
                                          N.sub.3 O.sub.4                 
                                                 57.67                    
                                                      6.12                
                                                          10.60           
57  6-Cl H   H  H  3 OH          H   255-258                              
                                          C.sub.19 H.sub.24 Cl            
                                                 53.03                    
                                                      5.86                
                                                           9.76           
                                          N.sub.3 O.sub.4.HCl             
                                                 53.14                    
                                                      5.62                
                                                           9.76           
58  6-Cl H   C.sub.2 H.sub.5                                              
                C.sub.2 H.sub. 5                                          
                   4 OH          H   177-179                              
                                          C.sub.23 H.sub.32 Cl            
                                                 61.40                    
                                                      7.17                
                                                           9.34           
                                          N.sub.3 O.sub.4                 
                                                 61.25                    
                                                      7.11                
                                                           9.37           
59  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   4 OH          H   186-187                              
                                          C.sub.22 H.sub.30 F             
                                                 57.96                    
                                                      6.85                
                                                           9.22           
                                          N.sub.3 O.sub.4.HCl             
                                                 57.77                    
                                                      6.84                
                                                           9.06           
60  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 O               154-156                              
                                          C.sub.21 H.sub.26 F             
                                                 62.52                    
                                                      6.50                
                                                          10.42           
                                          N.sub.3 O.sub.4                 
                                                 62.37                    
                                                      6.46                
                                                          10.32           
61  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 O               153-155                              
                                          C.sub.21 H.sub.26 F             
                                                 57.34                    
                                                      6.19                
                                                           9.55           
                                          N.sub.3 O.sub.4.HCl             
                                                 57.25                    
                                                      6.02                
                                                           9.37           
62  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 OCOCH.sub.3 H   216-219                              
                                          C.sub.23 H.sub.30 F             
                                                 57.08                    
                                                      6.46                
                                                           9.68           
                                          N.sub.3 O.sub.5.HCl             
                                                 56.90                    
                                                      6.27                
                                                           8.63           
63  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3                                                      
                      ##STR38##  OH  169-172                              
                                          C.sub.27 H.sub.32 F N.sub.3     
                                          O.sub.4.HCl                     
                                                 62.60 62.57              
                                                      6.42 6.51           
                                                           8.11 8.23      
64  8-Cl H   H  H  3 OH          H   144-146                              
                                          C.sub.19 H.sub.24 Cl            
                                                 57.94                    
                                                      6.14                
                                                          10.67           
                                          N.sub.3 O.sub.4                 
                                                 57.71                    
                                                      6.08                
                                                          10.51           
65  8-Cl H   H  H  3 OH          H   274-276                              
                                          C.sub.19 H.sub.24 Cl            
                                                 53.03                    
                                                      5.86                
                                                           9.76           
                                          N.sub.3 O.sub.4.HCl             
                                                 52.94                    
                                                      5.62                
                                                           9.63           
66  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3                                                      
                      ##STR39##  H   158-160                              
                                          C.sub.28 H.sub.32 Cl FN.sub.3   
                                          O.sub.4.HCl                     
                                                 59.37 59.24              
                                                      6.05 6.08           
                                                           7.42 7.24      
67  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   2 OH          H   169-170                              
                                          C.sub.20 H.sub.26 F             
                                                 61.37                    
                                                      6.70                
                                                          10.73           
                                          N.sub. 3 O.sub.4                
                                                 61.34                    
                                                      6.80                
                                                          10.56           
68  H    H   H  H  3 OH          H   150-152                              
                                          C.sub.19 H.sub.25 N.sub.3       
                                                 63.49                    
                                                      7.01                
                                                          11.69           
                                          O.sub.4                         
                                                 63.53                    
                                                      7.15                
                                                          11.66           
69  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3 H           H   256-258                              
                                          C.sub.21 H.sub.28 F             
                                                 59.22                    
                                                      6.86                
                                                           9.87           
                                          N.sub.3 O.sub.3.HCl             
                                                 59.15                    
                                                      6.78                
                                                          10.01           
70  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3                                                      
                      ##STR40##      146-148                              
                                          C.sub.23 H.sub.28 F N.sub.3     
                                          O.sub.5                         
                                                 61.73 61.57              
                                                      6.76 6.91           
                                                           9.39 9.27      
71  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   3                                                      
                      ##STR41##  H   132  C.sub.27 H.sub.32 F N.sub.3     
                                          O.sub. 3                        
                                                 69.66 69.50              
                                                      6.93 6.91           
                                                           9.03 8.93      
72  6-F  H   CH.sub.3                                                     
                CH.sub.3                                                  
                   6 OH          H   145-146.5                            
                                          C.sub.24 H.sub.34 F             
                                                 64.41                    
                                                      7.66                
                                                           9.39           
                                          N.sub.3 O.sub.4                 
                                                 64.21                    
                                                      7.73                
                                                           9.34           
73  6-Cl H   CH.sub.3                                                     
                CH.sub.3                                                  
                   4 OH          H   87-89                                
                                          C.sub.22 H.sub.30 Cl            
                                                 60.61                    
                                                      6.94                
                                                           9.64           
                                          N.sub.3 O.sub.4                 
                                                 60.57                    
                                                      6.75                
                                                           9.58           
74  6-Cl H   C.sub.2 H.sub.5                                              
                C.sub.2 H.sub.5                                           
                   3 OH          H   174-177                              
                                          C.sub.23 H.sub.32 Cl            
                                                 61.39                    
                                                      7.17                
                                                           9.34           
                                          N.sub.3 O.sub.4                 
                                                 61.29                    
                                                      7.22                
                                                           9.26           
75  6-Cl H   CH.sub.3                                                     
                CH.sub.3                                                  
                   5 OH          H   136-139                              
                                          C.sub.23 H.sub.32 Cl            
                                                 61.39                    
                                                      7.17                
                                                           9.34           
                                          N.sub.3 O.sub.4                 
                                                 61.25                    
                                                      7.27                
                                                           9.35           
76  6-Cl H   CH.sub.3                                                     
                CH.sub.3                                                  
                   7 OH          H   122-124                              
                                          C.sub.25 H.sub.36 Cl            
                                                 62.81                    
                                                      7.59                
                                                           8.79           
                                          N.sub.3 O.sub.4                 
                                                 62.88                    
                                                      7.61                
                                                           8.90           
77  6-Cl H   CH.sub.3                                                     
                CH.sub.3                                                  
                   6 OH          H   131-134                              
                                          C.sub.24 H.sub.34 Cl            
                                                 62.13                    
                                                      7.39                
                                                           9.06           
                                          N.sub.3 O.sub.4                 
                                                 62.18                    
                                                      7.28                
                                                           9.01           
__________________________________________________________________________
 
    
     
                                           TABLE 8                                 
__________________________________________________________________________
 ##STR42##                                                                
                                                 Elementary analysis      
                                                 (upper column:           
                                                 calculated, lower        
Exam-                                    Molecular                        
                                                 column: found)           
ple  X.sup.1                                                              
        X.sup.2                                                           
           R.sup.1                                                        
              R.sup.2                                                     
                 n  R.sup.3    R.sup.4                                    
                                   m.p. (°C.)                      
                                         formula C (%)                    
                                                      H                   
                                                           N              
__________________________________________________________________________
                                                           (%)            
78   6-Cl                                                                 
        H  CH.sub.3                                                       
              CH.sub.3                                                    
                 3                                                        
                     ##STR43##  H  129-131                                
                                         C.sub.23 H.sub.26 ClN.sub.3      
                                         O.sub.3 64.56 64.35              
                                                      6.12 6.33           
                                                            9.82 9.71     
79   6-Cl                                                                 
        H  CH.sub.3                                                       
              CH.sub.3                                                    
                 3                                                        
                     ##STR44## CH.sub.3                                   
                                   173.5-175                              
                                         C.sub.21 H.sub.29 ClN.sub.4      
                                         O.sub.3 59.92 59.90              
                                                      6.94 6.90           
                                                           13.31 13.21    
__________________________________________________________________________
 
    
     
                                           TABLE 9                                 
__________________________________________________________________________
 ##STR45##                                                                
                                                 Elementary analysis      
                                                 (upper column:           
                                                 calculated, lower        
Exam-                                    Molecular                        
                                                 column: found)           
ple  X.sup.1                                                              
         X.sup.2                                                          
             R.sup.1                                                      
                  R.sup.2                                                 
                     n  R.sup.5                                           
                              R.sup.6                                     
                                   m.p. (°C.)                      
                                         formula C (%)                    
                                                      H                   
                                                           N              
__________________________________________________________________________
                                                           (%)            
80   6-NO.sub.2                                                           
         H   CH.sub.3                                                     
                  CH.sub.3                                                
                     3  OH    H    173.5-175                              
                                         C.sub.21 H.sub.28 N.sub.4        
                                         O.sub.6  58.32                   
                                                      6.53 12.96          
                                                 58.02                    
                                                      6.53 12.96          
81   6-NO.sub.2                                                           
         8-NO.sub.2                                                       
             CH.sub.3                                                     
                  CH.sub.3                                                
                     3  OH    H    202-204                                
                                         C.sub.21 H.sub.27 N.sub.5        
                                         O.sub.8 52.83                    
                                                      5.70 14.67          
                                                 52.80                    
                                                      5.90 14.55          
82   6-CF.sub.3                                                           
         H   H    H  3  OH    H    188-190                                
                                         C.sub.20 H.sub.24 F.sub.3        
                                         O.sub.4 56.20                    
                                                      5.66  9.83          
                                                 56.10                    
                                                      5.78  9.80          
83   6-Cl                                                                 
         H   CH.sub.3                                                     
                  CH.sub.3                                                
                     3                                                    
                         ##STR46## H waxy                                 
                                         C.sub.31 H.sub.46 ClN.sub.3      
                                         O.sub.5 64.62 64.65              
                                                      8.04 8.23           
                                                            7.29 7.07     
84   6-CF.sub.3                                                           
         CH.sub.2 O                                                       
             H CH.sub.3                                                   
                  CH.sub.3                                                
                     3  OH    H    waxy  C.sub.23 H.sub.3 F.sub.3 N.sub.3 
                                         O.sub.5 56.9  6.23               
                                                            8.66          
                                                 56.6 6.03  8.60          
__________________________________________________________________________
 
    
     Embodiments of the present invention will be illustrated in the following formulations 1 and 2. The principal ingredient used was 2,2-dimethyl-6-fluoro-1&#39;-[4-(4-hydroxypiperidino)butyl]spiro[chroman-4,4&#39;-imidazolidine]-2&#39;,5&#39;-dione hydrochloride. 
     
         ______________________________________                                    
Formulation 1: Tablet                                                     
______________________________________                                    
principal ingredient   10.0   parts                                       
lactose                53.5                                               
microcrystalline cellulose                                                
                       18.0                                               
corn starch            18.0                                               
calcium stearate       0.5                                                
______________________________________                                    
 
    
     The above-mentioned components were mixed together by a conventional method and then granulated. The granules were compression-molded into tablets each weighing 100 mg. 
     
         ______________________________________                                    
Formulation 2: Capsule                                                    
______________________________________                                    
principal ingredient  10.0   parts                                        
lactose               70.0                                                
corn starch           20.0                                                
______________________________________                                    
 
    
     Capsules each weighing 100 mg were prepared by a conventional method according to the above recipe.