4-Alkoxy-N-aminonaphthalic acid imides as optical brightners
United States Patent 91 [111 3,830,857 Scheuermann 1 1 Apr. 29, 1975 1 4-ALKOXY-N-AM1NONAPHTHALIC ACID IMIDES AS OPTICAL BRIGHTNERS [75] Inventor: Horst Scheuermann, Ludwigshafen.  
 Germany [73] Assignee: Badische Anilin- &amp; Soda-Fabrik Aktiengesellschatt, Ludwigshafen. Germany [22] Filed: Aug. 26. 1971 21 App1.No.: 175,327  
 [30] Foreign Application Priority Data Sept. 3. 1970 Germany 1. 2043662 [52] US. Cl. 260/281; 8/11 W; 260/247.1 L; 260/2472 A [51] Int. Cl C07d 39/00 [58] Field of Search 260/281 [56] References Cited UNITED STATES PATENTS 2.006.017 6/1935 Eckcrl .1 260/281 2.600.080 6/1952 Shrader... 260/281 3.310.564 3/1967 Kasai 260/281 3.330.834 7/1967 Scnshu 260/281 3.546.227 12/1970 Gmundler et a1 260/281 3.661.912 5/1972 Kalz 260/281 3.697.526 10/1972 Pugin 260/281 3.798.224 3/1974 Hotta 11 260/281 FOREiGN PATENTS OR APPLICATIONS 2.064.159 7/1971 Germany U 260/281 OTHER PUBLICATIONS Dine-Hart, Jour. Polymer Sci. V01. 6. pp. 2755-2764 (1968).  
 Primary ExaminerDonald G. Daus Attorney. Agem. or Firm-Johnston. Keil. Thompson &amp; Shuttleff [57] ABSTRACT Optical brighteners of the formula:  
 derived from 4-21lkoxy-N-aminonaphthahc acid imides. The compounds are useful for brightening acrylonitrile polymers, polyamides, cellulose esters and polyesters.  
 1 Claim, No Drawings 1 4-ALKOXY-N-AMINONAPHTHALIC ACID IMIDES AS OPTICAL BRIGHTNERS The invention relates to optical brighteners having the general formula (I):  
 or Y  
 where X denotes hydrogen. chlorine. methyl. methoxy. cthoxy. carbomethoxy or carboethoxy. and Y denotes hydrogen, chlorine. bromine or the radical OR.  
  Examples of alkyl radicals R are unsubstituted or substituted linear or branched alkyl groups having one to four carbon atoms. Specific examples of R are methyl. ethyl. isopropyl. butyl. isobutyl. benzyl. phenylethyl. methoxyethyl. butoxyethyl or cyclohexyl.  
  Examples of radicals R are linear or branched groups having up to eight carbon atoms which may bear cyano. chlorine. bromine, alkoxy or dialkylamino as substituents. Aryl radicals R may for example bear chlorine. bromine. methyl. ethyl. methoxy. ethoxy, dimethylamino. earbomethoxy. carboethoxy or cyano as substituents. Heterocyclic radicals R may be derived for example from thiophene. furan. thiazole. imidazole. pyridine or quinoline.  
  Specific examples of R are: methyl. ethyl. n-propyl. isopropyl. n-butyl. isobutyl. a-ethylpentyl. chloromethyl. methoxymethyl. ethoxymethyl. B-methoxyethyl. B-ethoxyethyl. B-butoxyethyl. cyanomethyl.  
  B-diethylaminoethyl. a-morpholinomethyl. a-N-methylpiperazinomethyl. phenyl. o-chlorophenyl. m-chlorophenyl. pchlorophenyl. 3.4dichlorophenyl. 2-chloro-4- methylphenyl. o-methylphenyl. mmethylphenyl. pmethylphenyl. o-methoxyphenyl. m-methoxyphenyl. p-methoxyphenyl. o-ethoxyphenyl. m-ethoxyphenyl. p-ethoxyphenyl. p-bromophenyl. p-cyanophenyl. p-carbomethoxyphenyl. p-carboethoxyphenyl. 2- thenyl. 5-chloromethyI-Z-thenyl, 2-furyl. 5 chloromethyl-Z-furyl. 2-amino-4-methylthiazolyl-( 5 Z-phenyl-4-methylthiazolyl-( 5 4-imidazolyl. 3- pyridinyl. 4-pyridinyl. 4-quinolinyl. 8-quinolinyl. meth- B-dimethylaminoethyl. B-dibutylaminoethyl. a-piperidinomethyl.  
  oxy. ethoxy. butoxy. phenoxy. ethylamino.  
 propylamino. cyclohexylamino. phenylamino. mmethylphenylamino. m-chlorophenylamino. pchlorophenylamino or 3.4-dichlorophenylamino.  
 Examples of R in addition to hydrogen. are: methyl.  
  ethyl. butyl. cyclohexyl. benzyl. phenylethyl. phenyl. p-chlorophenyl. m-methylphenyl. p-methylphenyl. psulfonamidophenyl, p-N,N-dialkylsulfonamidophenyl. p-carbomethoxyphenyl or p-carboethoxy phenyl and also the radicals having the formulae The invention relates in particular to compounds having the formula:  
  5 R -N-C n 40 R in which R denotes alkyl having one to four carbon atoms or methoxyethyl&#39;.  
 R denotes alkyl having one to seven carbon atoms.  
 chloromethyl. cyanomethyl. alkoxyalkyl having a total of two to six carbon atoms. phenyl. chlorophenyl.  
  methylphenyl. methoxyphenyl. ethoxyphenyl or a radical of the formula:  
  ca u o str am-0H c u N(cH oro R denotes hydrogen. alkyl having one to four carbon atoms or phenyl;  
 R and R together with the groups attached to them may denote a radical having the formula:  
 X denotes hydrogen. chlorine. methyl or methoxy; and Y denotes hydrogen. chlorine or the radical OR Compounds having special industrial importance are those having the general formula:  
  h 6 R -iy c o 0 o C (II) where R has the meanings given above. R denotes hydrogen. methyl or phenyl; and R and R together denote a radical having the formula Heterocyclic radicals R are preferred.  
 The production of compounds having the formula (I) 40 may be carried out for example according to the following scheme:  
  The reactions are known in principle and proceed analogously under comparable conditions.  
  The compounds having the formula (I) are colorless to pale yellow and are suitable as optical brighteners [5 for synthetic fibers such as acrylonitrile polymers, poly- 15 cool. The reaction mixture is poured onto 200 parts of ice. stirred for one hour and the precipitate suction filtered. washed with water and dried. 18.7 parts (66% of theory) of the compound having the constitution:  
 is obtained which, after recrystallization from nbutanol. melts at from 194 to 195C.  
  R v 0 O o o N o H 2 H N-NR A A A Cl 01&#34; B1&#34; l ROH n iy-co-Pt R an: O O acylation N O OR OR Naphthalic anhydride-4sulfonic acid may also be re- (,5 The 4&#39;methoxyN-aminonaphthalimide required for acted with a hydrazine having the formula: the production of this acetyl compound is prepared as H- NNHR the sulfonic acid group replaced by a hydroxyl group. the latter alkylated with introduction of the radical R and the intermediate thus obtained acylated with the introduction of the radical R-CO.  
 follows: 246.5 parts of 4-chloro-N-aminonaphthalimide is suspended in 800 parts of methanol and then 240 parts of a 30% solution of sodium methylate in methano! is added. This mixture is then boiled for nine hours.  
 acidified with glacial acetic acid and stirred into L000 parts of water. The precipitate is suction filtered, washed with water and dried. 220 parts (91% of theory) of 4-methoxy-N-aminonaphthalimide is obtained parts of acetone is dripped at to C into a suspension of2412 parts of 4-methoxy-N-aminonaphthalimide and l3.8 parts of potassium carbonate in parts of acetone. After stirring for three hours a pH of 3 to 4 is which melts at 241 to 242C 5 set up with glacial acetic acid and the mixture is stirred I into 300 parts of water. The precipitate is suction filobmmed by the tered. washed with water dried and recrystallized from followmg f 9 of 232&#39;s parts of methanol. 25 parts (84% of theory) of the compound chloronaphthalic anhydride in 700 parts of dtmethylhaving the consflwfinni formamide is heated to to C and then 55 parts ll) of hydrazine hydrate is dripped in. After the whole has 9 been stirred for four hours at 130 to 140C it is cooled to 5 to 10C, and the precipitate is suction filtered. 1 2 j washed with 200 parts of methanol and dried. parts 0 O (77% of theory) of 4-chloro-N-aminonaphthalimide is 15 I obtained having a melting point of 223 to 225C. n l I l The following naphthalimide derivatives are obtained analogously to Example l from the corresponding 4 OCH alkoxy-N-aminonaphthalimides with acetic anhydride: 3  
  O N CH R 1 a. 5 o N 0 Example R R&#39; Melting point: C)  
 2 C H H 212 to 21 4 3 CH CH OCH3 H 101 to 102 l CH CH 2 BO 2H2 5 H c 11 198 to 199 EXAMPLE 6 is obtained which meat at 231 to 232C,  
  The following naphthalimide derivatives are pre- A solution of l 1.1 parts of propionyl chloride in 25 45 pared analogously to Example 6:  
  0 H R l IC-R i N v F&#34; O 1 l OCH Example R a Melting point 0) CH 7 CH; 3 H 21 to 215 8 -CH -01 H 265 to 26&amp;  
  C H 9 -CH 2 5 H 190 to 191 1 1310 R R Melting point; il)  
 10 4 11 H 210 to 211 11 ca a 266 to 267 CH 12 -CH2-CH: 5 CH 155 to 155 c H 1 1 4:15: 2 5 c 11 151 to 152 EXAMPLE I5 EXAMPLE [8 is obtained which melts at 223 to 225C.  
  The following naphthalimide derivatives are obtained as in Example 13 with the appropriate carboxylic acid chlorides:  
  l7.8 parts of phthalic anhydride is introduced at to C into a solution of 24.2 parts of 4-methoxy-N- aminonaphthalimide in 120 parts of pyridine. The mixture is stirred for five hours at 70 to 75C cooled to 20 to 25C, 300 parts of water is added and the precipitate is suction filtered washed with water, dried and recrystallized from methyl glycol. 23 parts ((12% of theory) of the compound is obtained. The compound melts at 297 to 299C.  
 EXAMPLE l9 [9.8 parts of naphthalic anhydride is added at to 9 m -c-R 0 i N t Example R Melting point; (0C) H c 17 3 266 to 267 S 100C to a solution of 242 parts of 4-methoxy-N- aminonaphthalimide in 350 parts of glacial acetic acid. The solution is heated for 6 hours at 115 to 120C. stirred into 1.000 parts of water and the precipitate is suction filtered. washed with water. dried and recrystallized from dimcthylformamide. 24 parts (57% of theory) of the compound having the formula:  
 OCH  
 is obtained which melts at 330 to 334C.  
 EXAMPLE 46.1 parts of the compound having the formula:  
 is suspended in 300 parts of methanol and then 144 parts of a 3071 solution of sodium methylate is added to the mixture. The mixture is heated for 24 hours at 65 to 70C. acidified with glacial acetic acid. stirred into 1.000 parts of water. suction filtered. washed with water and methanol and dried. 23 parts (51% 0f theory) of the compound having the formula:  
 is obtained which melts at 330 to 336C.  
 EXAMPLE 21 13.1 parts of phenyl isocyanate is dripped at 65 to is obtained which melts at 295 to 296C.  
 EXAMPLE 22 14.1 parts of ethyl chloroformate is added to 31.8 parts of 4-methoxy-N-phenylaminonaphthalimide in 150 parts of nitrohenzene and this mixture is heated for eight hours at 130 to 140C. The nitrobenzene is then removed by steam distillation and the residue is suction filtered. dried and recrystallized twice from isobutanol. 18 parts (46% of theory) of the compound having the formula:  
 OCH  
 is obtained which melts at 203 to 204C.  
 EXAMPLE 23 11.8 parts of maleic anhydride is added at to C to a solution of 24.2 parts of 4-methoxy-N-aminonaphthalimide in 120 parts of pyridine. the mixture is stirred for five hours at 80 to C. 300 parts of water is added and the precipitate is suction filtered. washed with water. dried and recrystallized several times from dimethylformamide and methanol. 7 parts (227: of thecry) of the compound having the formula: