Synthesis of the novel photographic DIAR couplers

The synthesis and characterization of six novel photographic DIAR couplers are reported. They are based on yellow couplers which can react with an oxidized color-developing agent to form yellow dyes; N-(ethylamido)-methyl-4-nitrophenol and 2-(isopropylamino)phenthiol, synthesized by a new method from benzothiazole, are used as timing groups to control the release of the inhibitor. The substituted tetrazole, 1,2,3-thiadiazole, benzothiazole and 1H-benzotriazole are used as the inhibiting groups. Two of the six novel couplers are the hydrolyzable inhibitor type of DIAR coupler. During preparation of the intermediates, triphosgene was substituted for phosgene and good results were obtained.