Patent GB-532726-A (GB)
Title: Improvements in or relating to colour photography
IPC: G03C7/384
Filed: 1939-07-22
Abstract: 532,726. Pyrazolones. KENDALL, J. D., and COLLINS, R. B. July 22, 1939, No. 21332. [Class 2 (iii)] [Also in Group XX] A colour former for incorporation in a colour developer containing an aromatic amino developing agent or in a silver halide emulsion as the general formula where R 1  is hydrogen or a hydrocarbon or heterocyclic group, and Y is an -OR 2 or -NR 3 R  4  group, where R 2  is a hydrocarbon group and R 3  and R 4  are the same or different and are hydrogen atoms or hydrocarbon groups, or together with the nitrogen atom constitute the residue of a heterocyclic nucleus. The colour formers of the type where Y is -NR 3 R 4  may be obtained by reacting a compound of the type where Y is -OR  2  with a diamine, particularly an aromatic diamine, so that the product contains two pyrazolone nuclei. The groups R 1 , R  2 , R  3  and R 4  may be methyl, ethyl, propyl, butyl, or higher alkyl phenyl, naphthyl, or benzyl groups. The aryl groups may be substituted with hydroxy, alkoxy, hydroxyalkyl, amino or nitro groups and may be halogen atoms. The groups R 3  and R 4 may together constitute a piperidine group, and R, may be a quinoline or benzthiazole group. Where Y is -OR 2  the colour formers may be prepared by condensing of di-ester of acetone-dicarboxylic acid with hydrazine or mono-substituted hydrazine, such as methyl hydrazine, ethyl-hydrazine, phenyl hydrazine substituted phenyl hydrazines, naphthyl hydrazines, substituted naphthyl hydrazines, and heterocyclic hydrazines such as quinoyl and benzthiazolyl hydrazines. Where Y is -NR 3 R 4  the amine may be mono dialkylamines such as ethylamine and diethylamine ; mono and di-arylamines such as aniline, diphenylamine, and naphthylamines ; mono- and di-aralkylamines such as benzylamine ; alkyl arylamines such as N-ethylamine ; aralkyl arylamines such as benzyl aniline ; heterocyclic amines such as pyridine, piperidine, quinoline, thiazoles, oxazoles, pyrimidines, and quinazolines ; and diamines such as o- and p-phenylene diamine, benzidine, dianisidine, diaminostilbenes and di-naphthyl amines. Aryl nuclei in the amines may be substituted by alkyl, nitro, helogen, alkoxy, or hydroxyalkyl groups. Examples specified are : (1) ethyl 1-phenyl-5- pyrazoline-3-acetate, prepared by the reaction of di-ethyl acetonediearboxylate with pbenylhydrazine ; (2) 1-phenyl-3-acetanilido-5-pyrazoline; (3) 1-phenyl-3-R-ethoxyacetanilido-5- pyrazolone ; (4) 1-phenyl-3-p-chloracetanilide- 5-pyrazolone; (5) di-(I-phenyl-5-pyrazolone-3- acet-benzidide ; (6) 1-phenyl-3-acet-d-naphthylamide-5-pyrazolone; (7) ethyl 1-#-naphthyl-5- pyrazolone-3-acetate ; (8) 1-#-naphthyl-3-pchloracetanilide-5-pyrazolone ; (9) 1-#-naphthyl 3-acet-o-anisidido-5-pyrazolone; (10) p-p<SP>1</SP>-di- (1-phenyl-5-pyrazolone-3-acetamino) - benzene; (11) p:p di-(1-phenyl-5-pyrazolone-3-acetamino)- m:m<SP>1</SP>-dimethoxydiphenyl ; (12) 1-phenyl-3- acet-n-butylamide-5-pyrazolone : (13) ethyl 1- p-chlorphenyl-5-pyrazolone-3-acetate ; (14) p:p<SP>1</SP> di-( 1-p-chlorphenyl-5-pyrazolone-3-acetamino )- diphenyl; (15) 1-p-chlorphenyl-3-acet-p-anisidido-5-pyrazolone; (16) ethyl 1-p-tolyl-5-pyrazolone-3-acetate; (17) 1-p-tolyl-3-(acet-2<SP>1</SP>:4<SP>1</SP>- dimethyl-anilido)-5-pyrazolone; and (18) p:p<SP>1</SP> di - ( 1 - p -tolyl - 5 - pyrazolone-3-acetamino)-diphenyl ; (19) examples (2) to (6) and (10) to (12) are prepared by reacting example (1), examples (8) to (9) by reacting example (7), examples (14) and (15) by reacting example (13) and examples (17) and (18) by reacting example (16) with the appropriate amine. The Provisional Specification refers also to colour formers having the general formula where n is a positive integer. Additional di-esters specified are those of #-keto-adipic acid and #-ketopimelic acid.