Improvements in colour photography

The invention comprises compounds of the formula: where M represents the colour coupling portion of the molecule and R1 and R2 are substituents such as alkyl groups and any of the benzene rings may contain substituents. Such compounds are employed as photographic colour couplers (see Division G2). In examples 4-{3 - [4 - (4 - dimethylaminostilbenzl) carbamoyl] phenyl thio} -2- (2,4- di - t - amylphenoxybutylcarbamoyl) -1- naphthol is prepared by reacting 3(4-dimethyl-aminostilben -4- yl - carbamoyl) phenyl sulphenyl chloride with 1-hydroxy -N- [5-(2,4-di-t-amylphenoxy)butyl] -2-naphthamide; a -benzoyl -a - 3 -[4-(41-dimethylaminostilbenzylcarbamoyl) phenylthio] acetamilide is obtained by reacting the above sulphenyl chloride with a -benzoylacetanilide; and 4-{3-[4 - (41-dimethylaminostilbenzl) carbamoyl] phenylthio} 2-carbamoylcyclohexyl -1- naphthol is obtained by reacting 3(4-dimethylaminostilbenzl -4- carbamoyl) phenyl sulphenyl chloride with 2-carboxycyclohexylamide -1- hydroxynaphthalene. 3:31-Dithiobenzoyl chloride is obtained by treating 3:31-dithiobenzoic acid with thionyl chloride. Di -[3-(4-dimethylaminostilben -4- yl - carbamoyl disulphide is obtained by reacting 3:31-dithiobenzoyl chloride with 4-dimethylamino -4-aminostilbene in acetonitrile solution in the presence of trimethylamine. 2-carboxycyclohexamido -1- hydroxy - naphthalene is obtained by heating 1-hydroxy -2-phenylnaphthoate with cyclohexylamine.