5H-{8 1{9 benzopyrano{8 3,4-d{9 pyridines
United States Patent [191 Lee [4 1 Apr. 15, 1975 5H-[1]BENZOPYRANO[3,4-D1PYRIDINES [75] lnventor: Cheuk Man Lee, Waukegan, Ill.  
 [73] Assignee: Abbott Laboratories, North Chicago, Ill.  
  22 Filed: July 13,1973  
  21 Appl. No.: 379,016  
 [52] U.S. Cl. 260/295 T; 260/297 T; 424/263;  
  424/266 [51] Int. Cl C07d 31/34 [58] Field of Search 260/295 T, 297 T [56] References Cited UNITED STATES PATENTS 3,635,993 l/l972 Pars et a]. 260/297 T Primary Examiner-Alan L. Rotman Attorney, Agent, or FirmRobert L. Niblack&#39;, Joyce R. Krei; Vincent A. Mallare [57] ABSTRACT 5l-l-[1]Benzopyrano[3,4-d]pyridines represented by the formula wherein each R is loweralkyl, R is alkyl, cycloalkyl wherein Y is a straight or branched chain alkylene group having from 1 to 10 carbon atoms and each R R and R are the same or different members of the group consisting of hydrogen, halo, trifluoromethyl or loweralkyl; and R is hydroxy, acyloxy or X is a straight or branched chain alkylene group having from 1 to 8 carbon atoms, and wherein R and R are the same or different members of the group consisting of hydrogen or loweralkyl, or  
 \/ (CH2) l) J wherein X is a straight or branched chain alkylene 3 Claims, No Drawings SH-[HBENZOPYRANOB,4-D]PYRIDINES DETAILED DESCRIPTION OF THE INVENTION This invention relates to novel benzopyrans and more particularly relates to H-[ 1 ]benzopyrano[3,4- dlpyridines represented by the formula wherein each R is loweralkyl, R is alkyl, cycloalkyl or wherein Y is a straight or branched chain alkylene group having from I to carbon atoms and each R R and R are the same or different members of the group consisting of hydrogen, halo, trifluoromethyl or loweralkyl; and R is hydroxy, acyloxy or ll -oc-x-u Wherein X is a straight or branched chain alkylene group having from I to 8 carbon atoms, and R and R are the same or different members of the group consisting of hydrogen or loweralkyl, or  
  As used herein, the term loweralkyl&#34; refers to C -C straight or branched chain alkyl groups including methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl. neo-pentyl, n-hexyl and the like.  
  The term &#34;alkyl&#34; refers to straight and branched chain alkyl radicals having from I to 20 carbon atoms such as methyl, n-amyl, 3-methyl-2-octyl, 2-nonyl, 2- eicosanyl and the like.  
  Cycloalkyl, as used herein, refers to cyclic saturated aliphatic radicals having 3 to 8 carbon atoms in a ring, such as cyclopropyl, ,cyclobutyl, cyclopentyl. cyclohexyl, cycloheptyl and cyclooctyl.  
  The term halo&#34; includes chloro, fluoro, bromo and iodo.  
  The term acyloxy&#34; refers to acetoxy, propionyloxy, butyryloxy and the like.  
  When R is an ester, the term pharmaceutically acceptable salts refers to acid addition salts prepared by reacting the basic esters of the benzopyrans with an organic or inorganic acid, or by reacting the benzopyrans with the salt of an appropriate acid. When R is hydroxy, the term refers to alkali metal, alkaline earth metal, ammonium and substituted ammonium salts such as hydrochloride, hydrobromide, sulfate, bisulfate, acetate, valerate, oleate, laurate, borate, benzoate, lactate, phosphate, tosylate, citrate, maleate, succinate, tartrate, napsylate and the like.  
  When R is hydroxy, the compounds of this invention are prepared by dehydrogenation of-the corresponding l,2,3.4-tetrahydro-5I-I[ l ]benzopyrano[3,4-d]pyridine with, for example, palladium on carbon in a boiling inert solvent, or by debenzylation and dehydrogenation of the corresponding N-benzyl l,2,3,4-tetrahydro compound. When R is hydroxy, and R is alkyl or cycloalkyl, the tetrahydro compounds can be prepared according to the method described in US. Pat. No. 3,576,798. When R is hydroxy, and R is the compounds are prepared according to the following reaction scheme:  
  RBI 3 -Y 0CH IIOAc R 0 R H, loweralkyl R-ll or halo RGY  R OH .HCl Q cooc n CH MgBr 3 R1 6 l I OH Y R Q Compounds wherein R is acyloxy are prepared by reacting the corresponding compound wherein R is hydroxy with the appropriate acyl anhydride such as acetic anhydride.  
 The esters of this invention, R  
 are prepared by reacting equimolar quantities of the corresponding benzopyranopyridine, and the appropriate acid or its salt, in the presence of a carbodiimide such as dicyclohexyl carbodiimide, in a suitable solvent such as methylene chloride, chloroform and the like.  
  Some of the heterocyclic acids which can be used in the process are:  
 &#39;y-piperidinobutyric acid,  
 y-morpholinobutyric acid,  
 &#39;y-( Z-methylpiperidino)-butyric acid,  
 fi-piperidinovaleric acid,  
 &#39;y-pyrrolidinobutyric acid,  
 B-piperidinopropionic acid,  
 &#39;y-thiomorpholinobutyric acid and homopiperidinoacetic acid Reaction between the benzopyranopyridine starting material and the heterocyclic acid, or salt thereof, is readily effected by combining about equimolar amounts of the reactants and a slight excess of a carbodiimide such as dicyclohexylcarbodiimide. The reaction proceeds readily at room temperature and is generally completed in about 4 to hours. After the reaction is terminated, the reaction mixture can be filtered to remove the by-product of dicyclohexylurea, and the solvent can be distilled off using a rotary evaporator. The residue can be directly crystallized from a suitable solvent such as benzene/ether or the residue can be chromatographed and the desired material isolated from the appropriate chromatographic fractions. If the basic esters are obtained, the acid addition salts such as those named above, if desired, can be prepared by methods well known in the art.  
  The compounds of this invention, in the form of the free bases, can be used as neutralizing agents since they form salts with acids.  
  The pharmacological activity of the compounds of this invention renders them useful as drugs although it should be understood that every compound of the invention will not necessarily have each activity possessed by the others.  
  The compounds of this invention are useful as analgesic agents, and generally at dosages of from 1 to 10 mg./kg. of body weight daily. The analgesic activity was established in the standard mouse writhing test [Whittle, Brit. J. P/zarmacoL, 22, 296 1964)] and confirmed in the hot plate assay [Woolfe, G. and MacDonald, A. D., J. P/zarmacol. Exper. T/1erap., 80, 300, [944)] and the rat tail flick test [DAmour and Smith. J. Pharmacol. Exper. T/1erap., 72: 74, (1941)]. The compounds are additionally useful as anti-anxiety agents and anti-depressant agents.  
  The following examples further illustrate this invention:  
 EXAMPLE I 5 ,S-Dimethyll 0-hydroxy-8-( 3-methyl-2-octyl )-5H- l ]benzopyrano[3,4-dlpyridine CHCH (CH CH3 EXAMPLE 2 EXAMPLE 3 EXAMPLE 5 5,5-Dimethyl-lO-hydroxy-8-( l-cyclohexylethyl)-5l-lll]benzopyrano[3,4-dlpyridine is prepared by dehydrogenating 5,5-dimethyll -hydroxy -8-( lcyclohexylethyl 23 ,4-tetrahydro-H- ll]benzopyrano[3,4-d1pyridine following the procedure of Example 1.  
 EXAMPLE 6 5.5-Dimethyl-l0-hydroxy-8-(3-cyclopropyl-2- propyl)-5H-[[]benzopyrano[3,4-dlpyridine is prepared by dehydrogenating 5,5-dimethyl-l0-hydroxy-8- 3-.cyclopropyl-2-propyl l .2,3,4-tetrahydro-5 H- [l]beniopyrano[3,4-d]pyridine following the procedure of Example 1.  
 EXAMPLE 7 1 5.5-Dimethyl l0-hydroxy-8-92-tetradecyl)-5H- [1]benzopyrano[-(-d]pyridine is prepared by dehydrogenating 5 ,5 -dimethyl- 1 O-hydroxy-S-(2-tetradecy1)- l,2,3,4-tetrahydro-5 H-[ l ]benzopyrano[ 3,4-d]pyridine following the procedure of Example 1.  
 EXAMPLE 8 5,5-Dimethyl-l0-hydroxy-8-(2-eicosyl)-5H- [l]benzopyrano[3,4-d]pyridine is prepared by dehydrogenating 5,5-dimethyl-l0-hydroxy-8-(2-eicosyl)- l,2,3,4-tetrahydro-5l-l-[ 1 benzopyrano[ 3 ,4-dlpyridine following the procedure of Example 1.  
 EXAMPLE 9 5,5-Dimethyl-l0 hydroxy-8-ethyl-5l-l- [l]benzopyrano[3,4-d1pyridine is prepared by dehydrogenating 5,5-dimethyl-l0-hydroxy-8-ethyl-l,2,3,4- tetrahydro-5H-[ l ]benzopyrano[3,4-d]pyridine; following the procedure of Example 1.  
 EXAMPLE 10 5,5-Dimethyl-lO-hydroxy-8-iso-propyl-5H- [l]benzopyranol3,4-d]pyridine is prepared by dehydroge&#39;nating 5 ,S-dimethyll O-hydroxy-8-iso-propyl- 1,2 ,3 ,4-tetrahydro-5H-[ l ]benzopyrano[ 3 ,4-d ]pyridine following the procedure of Example l. Y  
 EXAMPLE 1 l 5 .S-Dimethyll 0-hydroxy-8-( 2-hexyl )-5 H- [l]benzopyrano[3.4-dlpyridine is prepared by dehydrogenating. 5.,5-dimethyl-l0-hydroxy-8-(2-hexyl)- l,2.3.4-tetrahydro-5H-[ l]benzopyrano[3,4-d1pyridine following the procedure of Example 1.  
 EXAMPLE 12 IO-Acetoxy-S ,5-dimethyl-8-( 3-methyl-2-octyl )-5 H l l ]benzopyrano[ 3,4-d]pyridine.  
 ococn r (&#39;JHClKCH on CH A mixture of 3.53 g. 0.01 mole) of 5,5-dimethyl-l0- hydroxy-8-(3-methyl-2-octyl)-5H-[ 1 ]benzopyrano[3,4-d]-pyridine, 1.22 g. (0.012 mole) of acetic anhydride, and 5 ml. of pyridine was stirred at room temperature for 24 hours. The reaction mixture was evaporated in vacuo. andthe residue was taken up in ether. The ether solution was washed with water. dried .with anhydrous sodium sulfate, and evaporated in vacuoQ The residue was purified by chromatography on a Florosil activated aluminum magnesium silicate 22 mm X 30 inches column with chloroform to give the pure product. A  
 Calcd. for C H NO C, 75.91; H, 8.41; N, 3.54.  
 Foundz-C. 75.62; H, 8.52; N, 3.38.  
 EXAMPLE l3 lO-Acetoxy-S,5-dimethyl-8-ethyl-5H-[ 1 ]benzopyrano-[3.4-d]pyridine is prepared by reacting 5,5- dimethyll0-hydroxy-8-ethyl-5H-[ l ]benzopyrano[ 3,4- dlpyridine and acetic anhydride in the presence of pyridine according to the method of Example l2.  
  EXAMPLE l4 lOAcetoxy-S,5-dimethyl-8-n-pentyl-5H- l]benzopyrano[3,4-d]pyridine is prepared by reacting 5,5-dimethyl-l0-hydroxy-8-n-pentyl-5H- l ]benzopyrano[3,4-d1pyridine and acetic anhydride in the presence of pyridine according to the method of Example 12 EXAMPLE l5 l0-Acetoxy15.5-dimethyl-8-(2-heptyl)-5H- l]benzopyrano[ 3,4-d] pyridine is prepared by reacting 5 ,S-dimethyll 0-hydroxy-8-( 2-heptyl )-5 H- [l]benzopyrano[3,4-d]pyridine and acetic anhydride in the presence of pyridine according to. the method of Example 12.  
 EXAMPLE l6 lO-Acetoxy-S,5-dimethyl-8-( l-cyclohexylethyl )-5H- [l]-benzopyrano[3,4-d]pyridine is prepared by reacting 5,5-dimethyll 0-hydroxy-8-( l-cyclohexylethyl 5H-[l]benzopyrano[ 3,4-d]-pyridine and acetic anhydride in the presence of pyridine according to the method of Example &#39;12. t I  
 EXAMPLE 17 l O-Acetoxy-S ,5-dimethyl-8-( 3-cyclopropyl-2- propyl)-5H-[l]benzopyrano[3,4-dlpyridine is prepared by reacting 5.5-dimethyl-l-hydroxy-8-(3- cyclopropyl-Z-propyl )-H-[ l ]benzopyrano[3.4- d]pyridine and acetic anhydride in the presence of pyridine according to the method of Example 12.  
 EXAMPLE l8 l0-Acetoxy-5.5-dimethyl-8-( 2-tetradecyl)-5H-[ 1 benzopyrano[3.4-dlpyridine is prepared by reacting 5,5-dimethyl-l0-hydroxy-8-(Z-tetradecyl )-5H-[ 1 ]benzopyrano[3.4-d]-pyridine and acetic anhydride in the presence of pyridine according to the method of Example l2.  
 EXAMPLE l9 lO-Acetoxy-S.5-dimethyl-8-(2-eicosyl)-5H- l ]benzopyrano[3,4-dlpyridine is prepared by reacting 5.5-dimethyl-l0-hydroxy-8-(2-eicosyl)-5H- l ]benzopyrano[3,4-d1pyridine and acetic anhydride in the presence of pyridine according to the method of Example 12 EXAMPLE 2O lO-Acetoxy-S.5-dimethyl-8-n-butyl-5H-[ 1 ]benzopyrano-[3.4-d]pyridine is prepared by reacting 5.5- dimethyll O-hydroxy-S-n-butyl-SH- [llbenzopyranol3,4-d1pyridine and acetic anhydride in the presence of pyridine according to the method of Example l2.  
 EXAMPLE 21 l0-Acetoxy-5.S-dimethyl-8-iso-propyl-5H- l lbenzopyranol3.4-dlpyridine is prepared by reacting 5.5-dimethyl-lO-hydroxy-8-iso propyl-5H- l ]benzopyrano[3,4-d1pyridine and acetic anhydride in the presence of pyridine according to the method of Example 12.  
 EXAMPLE 22 lO-Acetoxy-S.5-dimethyl-8-(2-hexyl)-5H- l lbenzopyranol 3,4-d Ipyridine is prepared by reacting 5.5-dimethyl-l0-hydroxy-8-(2-hexyl)-5H- [l]benzopyrano[3.4-dlpyridine and acetic anhydride in the presence of pyridine according to the method of Example l2.  
 EXAMPLE 23 Preparation of 2-( 3.5-dimethoxyphenyl)-5-(4-fluorophenyl) pentane A solution of 77 g. of 3-(4-fluorophenyl)propylbromide in 300 ml. of ether was added dropwise over a 2 hour period to a refluxing solution of g. of magnesium in 100 ml. of ether. The reaction mixture was refluxed for an additional 30 minutes after the addition was completed. A solution of 68 g. of 3.5- dimethoxyacetophenone in 100 ml. of ether was then added dropwise to the reaction and the reaction mixture was refluxed for IV: hours. To the reaction was added 300 ml. of a saturated ammonium chloride solution dropwise with stirring. The layers were separated and the aqueous layer extracted with ether. The ether extract was dried over magnesium sulfate and the ether removed in vacuo to give an oil. An additional 1 1 L7 of 3(4-fluorophenyl)propylbromide was worked up in EXAMPLE 24 Preparation of 2-( 3,5-dihydroxyphenyl )-5-(4-fluorophenyl) pentane Fifty grams of the above prepared 2-(3,5- dimethoxyphenyl)-5-(4-fluorophenyl)pentane, 450 ml. of acetic acid and 180 ml. of 48pe&#39;rcent HBr in water were mixed. While cooling. the mixture was saturated with hydrogen bromide gas (approximately one-half hour). The reaction was placed in an 87 bath and stirred for 17 hours. The reaction was then concentrated in vacuo and the residue neutralized with K CO and NaHCO extracted with ether, treated with charcoal and MgSO and filtered to yield 45 g. of 2-(3,5- dihydroxyphenyl )-5-( 4-fluorophenyl )pentane as a brown oil which distills at l/0.0l mmHg.  
 Analysis Calcd. for C H O F: C, 74.20; H, 6.98.  
 Found: C, 73.56; H, 7.04.  
 EXAMPLE 25 Preparation of 2-Benzyl-8-[ 5-( 4-fluorophenyl )-2-pentyl]- l O-hydroxy- 5-oxol .2.3.4-tetrahydro-5H-[ l ]benzopyrano[3.4- d]pyridene hydrochloride To 45 g. of 2-(3,5-dihydroxyphenyl) 5-(4- fluorophenyl)-pentane dissolved in I00 ml. of methanesulfonic acid were added in portions, 57 g. of l-benzyl-3-keto-4-carbethoxy piperidine hydrochloride. While stirring. 68 g. of POCl were added and the solution was stirred for 5 days at room temperature.  
 Water (300 ml.) and l80 ml. of CHCl were then added and the reaction mixture stirred for 30 minutes. After the addition of I00 ml. of 15 percent NaOl-l, the reaction was stirred for an additional 10 minutes. The CHCl layer was separated and extracted with l0 percent HCI. The CHCl layer was concentrated and CH CN added thereto to yield 55 g. of the desired product as the hydrochloride salt. m.p. 254-256C.  
  Analysis Calcd. for: C, 70.80; H, 6.14; Cl, 6.97; N, 2.75. Found: C, 70.15; H, 6.17; Cl. 7.23; N, 2.74.  
 EXAMPLE 26 Preparation of Z-Benzyl-S.S-dimethyl-8-[S-(4-fluorophenyl)-2- pentyl l O-hydroxyl .2.3,4-tetrahydro- Sl-ll l ]benzopyrano[ 3.4-d]pyridine Sixty five grams of the above-prepared 2-Benzyl-8- [5-(4-fluorophenyl)-2-pentyll-IO-hydroxy-S-oxo- 1.2.3.4-tetrahydro-5H] l ]benzopyrano[3.4-dlpyridine hydrochloride were suspended in 300 ml. of Cl-lCL After adding a Kl-lCO solution. the reaction was stirred for 30 minutes. The chloroform layer was separated. dried over M380 concentrated taken up in benzene and concentrated again. The concentrate was taken up in 185 ml. of hot anisole and the resulting solution was added dropwise to a solution of Cl-l MgBr in anisole (prepared by adding 180 g. of cuasr in 500 ml. of ether to 40 g. of Mg in ml. of ether. evaporating the ether and adding 300 ml. of anisole). The reaction mixture was stored overnight at 62C. Water (200 ml.) was added slowly, followed by 400 ml. of 10 percent H SO The anisole was removed by steam distillation and the resulting solid was taken up in chloroform, neutralized with KHCO dried over MgSO concentrated and the product (36.5 g.), m.p. l88-l90C.. crystallized from CH CN.  
 EXAMPLE 27 5 ,5-Dimethyl-8-[ 5-( 4-fluorophenyl )-2-pentyl l O- hydroxy-5H-[ 1 ]benzopyrano[3,4-d ]pyridine EXAMPLE 28 5,5-Dimethyl-8-I 5-phenyl-2-pentyl]- l O-hydroxy-SH- [l]benzopyrano[3,4-d1pyridine is prepared from 5,5-  
 I dimethyl-8-[5-phenyl-2-pentyl]-10-hydroxy-1,2.3.4-  
  tet&#39;rahydro-5H-[ l ]benzopyrano[3,4-d]pyridine following the procedure of Example 27.  
 EXAMPLE 29 5,5-Dimethyl-8-( 3-methyl-2-octyl l O-[ 4-( piperidino butyryloxy)-5H-[ 1]benzopyrano[3,4-d]pyridine hydrochloride N ocoaza -n CH3 RC1 CH3 (&#39;31-lC1l(C11 on A mixture of 3.53 g. (0.01 mole) of 5,5-dimethyl-lhydroxy-8-( 3-methyl-2-octyl)-5 H-[ 1 ]benzopyrano[3,4-d]-pyridine, 2.07 g. (0.01 mole) of &#39;y-piperidinobutyric acid hydrochloride, 2.16 g. (0.0105 mole) of N,N&#39;-dicyclohexylcarbodiimide, and 160 ml. of dried methylene chloride was stirred overnight at room temperature. The reaction mixture was cooled at approximately C. for several hours and was filtered to remove dicyclohexylureas. The filtrate was evaporated in vacuo and the residue was dissolved in 12.5 ml. of methylene chloride and 50 ml. of cyclohexane. After standing overnight in the cold room (approximately 5C.), the mixture was filtered again and the filtrate was evaporated in vacuo. The residue was recrystallized from methylene chloride/ether, giving 4.1 g. of the product, m.p. 134l37.  
  Calcd. for: C H N O .HC1: C, 70.76; H, 8.72; N, 5.16. Found: C, 70.71; H, 8.91; N. 5.21.  
 EXAMPLE 30 5.5-Dimethyl-8-( l-pentyl)-10-[4-(piperidino)- butyryloxy]-5H-[ l ]benzopyrano[3,4-d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5- dimethyll0-hydroxy-8-( l-pentyl)-5H- [1]benzopyrano[3,4-d]pyridine and y-piperidinobutyric acid hydrochloride in the presence of dicyclohexylcarbodiimide.  
 EXAMPLE 3] 5,5-Dimethyl-8-( 2-heptyl l 0-[4- (piperidino)butyryloxy]-5H-[ 1 ]benzopyrano[ 3,4- d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl-8-(2-heptyl)-l0-hydroxy- 5H[ 1 ]benzopyrano[ 3,4-d]pyridine and y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 32 5.5-Dimethyl-8-( l-cyclohexylethy1)-10-[4- (piperidino )butyryloxy]-5H-[ 1 ]benzopyrano[ 3.4- d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl-l0-hydroxy-8-( l-cyclohexylethyl)- 5H[ 1 ]benzopyrano[3,4-d1pyridine and &#39;y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 33 5,5-Dimethyl-8-(3-cyclopropyl-2-propyl)-10-[4- (piperidino)-butyryloxy]-5H-[ 1 ]benzopyrano[3,4- dlpyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl-10-hydroxy-8-(3-cyclopropyl-2- propyl)-5 H-[ l ]benzopyrano[ 3,4-d1pyridine and y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl-carbodiimide.  
 EXAMPLE 34 5 ,5-Dimethyl-8-( Z-tetradecyl 1 0-1 4-( piperidino butyryloxy]-5H-[ 1 ]benzopyrano[ 3,4-d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5- dimethyl-10-hydroxy-8-(2-tetradecyl)-5H- [l]benzopyrano[3,4-d]pyridine and &#39;y-piperidinobutyric acid hydrochloridein the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 35 5 ,5-Dimethyl-8-(2-eicosyl)-10-[4-(piperidino)- butyryloxy]-5H-[ l ]benzopyrano[ 3,4-d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5- dimethyl-10-hydroxy-8-(2-eicosyl)-5H- 11 l ]benzopyrano[ 3,4-d]pyridine and &#39;y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 36 5.5-Dimethyl-8-ethyl-lO-[4-(piperidino)- butyryloxy]-5H-[ l ]benzopyrano[3.4-d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 55- dimethyl-l-hydroxy-8-ethyl-5H-[ l ]benzopyrano[3,4- d]pyridine and y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 37 ,5-Dimethyl-8-methyll 0-[ 4-( piperidino butyryloxy]-5H-{ l ]benzopyrano[3,4-d1pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5- dimethyl-l0-hydroxy-8-methyl-5H- [l ]benzopyrano[3,4-dlpyridine and &#39;y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 38 5.5-Dimethyl-8-iso-propyl-l0-[4-(piperidino)- butyryloxy]-5H-[ l ]benzopyrano[ 3,4-d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5- dimethyll O-hydroxy-8-iso-propyl-5H- [l ]benzopyrano[ 3 4-d]pyridine and y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 39 5,5-Dimethyl-8-(2-hexyl)-l0-[4-(piperidino)- butyryloxy]-5H-[ l]benzopyrano[3,4-d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5- dimethyl-l0-hydroxy-8-(2-hexyl)-5H- [l]benzopyrano[3,4-d]pyridine and y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 40 5,5-Dimethyl-8-[5-phenyl-2-pentyl1-10-[4- (piperidino)-butyryloxy]-5H-[ l ]benzopyrano[3,4- d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl-l0-hydroxy-8-[5-phenyl-2-pentyl1- 5H-[ 1 ]benzopyrano[3,4-d ]pyridine and y-piperidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 41 5,5-Dimethyl-8-(3-methyl-2-octyl)-l0-[4- (morpholino )-butyryl0xy]-5H-[ 1 ]benzopyrano[3,4- d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl-l0-hydroxy-8-(3-methyl-2-octyl)- 5H-[ 1 ]benzopyrano[3,4-d]pyridine and -y-morpholinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 42 5,5-Dimethyl-8-( 3-methyl-2-octyl)- l O- [4- (pyrrolidino) butyryloxy]-5H-[ 1 ]benzopyrano[3,4 d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl-l0-hydroxy-8-(3-methyl-2-octyl)- 5H-[ 1 ]benzopyrano[ 3,4-d1pyridine and y-pyrrolidinobutyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 43 5,5-Dimethyl-8-(3-methyl-2-octyl)-10-[4-(2- methylpiperidino)butyryloxy1-5H- l ]benzopyrano[3,4-djpyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl-10-hydroxy-8- (3-methyl-2-octyl)-5H-[ 1 ]benzopyrano[3,4- d]pyridine and y-(2-methylpiperidino)butyric acid hydrochloride in the presence of dicyclohexyl carbodiimide.  
 EXAMPLE 44 EXAMPLE 46 5 ,5-Dimethyl-8-( 3-methyl-2-octyl l 0-[ 3- (piperidino) propionyloxy1-5 H-[ l ]benzopyrano[ 3,4-  
 d]pyridine hydrochloride is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl-lO-hydroxy-8-(3-methyl-2-octyl)- 5H-[ 1 ]benzopyrano[ 3,4-d1pyridine and B-piperidinopropionic acid in the presence of dicyclohexyl carbodiimide&#39;.  
 EXAMPLE 47 5 ,5-Dimethyl-8-( 3-methyl-2-octyl l 0- 4- (thiomorpholino )butyryloxy 1-5 H- [l]benzopyrano[3,4-d1pyridine hydrobromide is prepared according to the method of Example 29 by reacting equimolar quantities of 5,5-dimethyl- 10-hydroxy-8- (3-methyl-2-octyl)-5H-[ l ]benzopyrano[ 3,4- d]pyridine and y-thiomorpholinobutyric acid hydrobromide in the presence of dicyclohexyl carbodiimide.  
  The compounds of this invention can also be prepared by the simultaneous dehydrogenation and debenzylation of the corresponding N-benzyl-l ,2,3,4-tetrahydro-benzopyranopyridine as illustrated in the following example. The N-benzyl compound can be prepared according to the method described in US. Pat. No. 3,576,798.  
 5.5-Dimethyl-l0-ihydroxy-8-(3Qrnethyl-2-octyU-5H- l ]benzopyrano[3,4-d]pyridine A mixture of 2.23 g. of 2-benzyl-5,5-dimethyl-l0- hydroxy-8-( 3-methyl-2-octyl l ,2,3,4-tetrahydro-5H- ll]benzopyrano[3,4-dlpyridine, 0.8 g. (10 percent) palladium on carbon, and I ml. of xylene was stirred and refluxed for 24 hours. After removal of the catalyst, the filtrate was evaporated in vacuo and the residue was recrystallized from acetonitrile; m.p. l54-l56.  
  The present invention includes within its scope, pharmaceutical compositions comprising, as an active in gredient, at least one of the compounds of this invention in association with a pharmaceutically acceptable carrier or diluent. The compounds of this invention exhibit both oral and parenteral activity and can be formulated in dosage forms for oral, parenteral or rectal administration.  
  Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In such solid dosage forms, the active compound is admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms can also comprise, as is normal practice, additional substances other than inert diluents, e.g., lubricating agents such as magnesium stearate, and sweetening and flavoring agents. Tablets and pills can additionally be prepared with enteric coatings.  
  Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs containing inert diluents commonly used in the art, such as water. Besides inert diluents, such compositions can also include adjuvants, such as wetting agents, emulsifying and suspending agents and sweetening, flavoring and perfuming agents.  
 Preparations according to this invention for parenteral administration include sterile aqueous or nonaqueous solutions, suspensions or emulsions. Examples of non-aqueous solvents or vehicles are propylene glycol, polyethylene glycol, vegetable oils, such as olive oil, and injectable organic esters such as ester oleate. Such dosage forms may also contain adjuvants such as preserving, wetting, emulsifying and dispersing agents. They may be sterilized by, for example, filtration through a bacteria-retaining filter, by incorporating sterilizing agents into the compositions, by irradiating the compositions, or by heating the compositions. They can also be manufactured in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use.  
  Compositions for rectal administration are suppositories which may contain in addition to the active substance, excipients such as cocoa butter or a suppository wax.  
  The dosage of active ingredient in the compositions of this invention may be varied; however, it is necessary that the amount of the active ingredient shall be such that a suitable dosage form is obtained. The selected dosage depends upon the desired therapeutic effect, on the route of administration and on the duration of the treatment.  
  The following example further illustrates the pharmaceutical compositions which are a feature of this invention:  
  EXAMPLE 49 Tablets weighing 200 mg. and having the following composition are prepared by standard tableting procedures:  
 wherein each R is lower alkyl, R, is lower alkanoyloxy and R is lower alkyl, cycloalkyl or ,5! i gm wherein Y is a straight or branched chain alkylene group having from 1 to carbon atoms and each R R and R are the same or different members selected from the group consisting of hydrogen halo, trifluoromethyl or loweralkyl.  
  2. A compound in accordance with claim 1, l0- acetoxy-5,5-dimethyl-8-(3-methyl-2-octyl)-5H- [l ]benzopyrano [3,4-d]pyridine.  
  3. A compound in accordance with claim 1 wherein R is lower alkanoyloxy and R is wherein Y is a straight or branched chain alkylene group having from 1 to 10 carbon atoms and each R R and R are the same or different members of the group consisting of hydrogen, halo, trifluoromethyl or loweralkyl.