Patent GB-830797-A (GB)
Title: New colour couplers for use in colour photography
Inventor: GREENHALGH COLIN WILLIAM
IPC: G03C7/32
Filed: 1957-03-20
Abstract: The invention comprises colour couplers of the formula A-NHCO-CHR1-CHR2-COOY, wherein Y is hydrogen or an alkyl, cycloalkyl or aralkyl radical, either R1 or R2 is hydrogen and the other is -N.R3.acyl or <FORM:0830797/IV (b)/1> where R3 is hydrogen or an alkyl, cycloalkyl, aralkyl or aryl radical (the latter optionally substituted by sulpho, chloro, methoxy or cyano), Z is ethylene, phenylene or tetrahydrophenylene and "acyl" is exemplified by aliphatic and aromatic carboxylic and sulphonic acid acyl radicals, and A-NH- is the residue of a colour coupler containing an amino group and being one of the following: (1) those which contain a -CO-CH2-CO- group and which give yellow dyestuffs on colour development with substituted para-phenylenediamines, e.g. 41 - methoxybenzoylacet - 4 - amino - 2 - methoxy-anilide; (2) those which contain a cyanoacetyl group or a pyrazolone ring and which give magenta dyestuffs on colour development with substituted paraphenylenediamines, e.g. 4 - o  - cyanoacetylaniline, 1 - phenyl - 3 - amino- 5 - pyrazolone and 1 - phenyl - 3 - (41 - amino-phenyl) - 5 - pyrazolone; and (3) amino-phenols and amino-1-naphthols which give cyan dyestuffs on colour development with substituted para-phenylenediamines, e.g. 1-amino - 5 - naphthol and 4 - chloro - 5 - methyl2-aminophenol. Alkali metal salts of the above compounds are also described.  The compounds are prepared by reacting colour couplers of the formula A-NH2 with anhydrides of the formula <FORM:0830797/IV (b)/2> or <FORM:0830797/IV (b)/3> and, if desired, esterifying the products to convert Y from hydrogen to an appropriate esterifying residue.  1 - Phenyl - 3 - (41 - nitrobenzylamino) - 5 - pyrazolone, 1 - phenyl - 3 - (41 - nitrophenoxyacetylamino) - 5 - pyrazolone and 1 - phenyl-3 - (41 - nitrophenylacetylamino) - 5 - pyrzolone are prepared by reacting 1-phenyl-3-amino-5-pyrazolone with para-nitrobenzylchloride, 4-nitrophenoxyacetyl chloride and 4-nitrophenylacetyl chloride, respectively, and are reduced to the corresponding 41-amino-compounds.  1 - (41 - Carbethoxyphenyl) - 3 - amino - 5 - pyrazolone is obtained by reacting together 4-carbethoxyphenyl-hydrazine, ethyl b -ethoxy-b -iminopropionate hydrochloride and potassium hydride. Compounds of the formula <FORM:0830797/IV (b)/4> are prepared by reacting aminosuccinic acid with an anhydride of an ethylene, phenylene or tetrahydrophenylene dicarboxylic acid and treating the product with a dehydrating agent such as acetic anhydride. Compounds of the formula <FORM:0830797/IV (b)/5> are prepared either by heating acids of the formula <FORM:0830797/IV (b)/6> with an acid chloride or anhydride, or by reacting an ester of maleic acid with an amine R3.NH2, treating the product with an acid chloride or acid anhydride, hydrolysing off the ester groups, and subsequently treating with a dehydrating agent such as acetic anhydride. Compounds of the formula <FORM:0830797/IV (b)/7> are obtained (e.g. as the disodium salt) by reacting maleic acid or maleic anhydride with an amine R3.NH2 in presence of an alkali.