Synthesis and photographic properties of novel development-accelerator-releasing couplers

Several novel development-accelerator-releasing couplers (DAR couplers) were synthesized. The structure of DAR couplers was confirmed by MS, IR and1H NMR spectroscopy. At the same time, the effect of DAR couplers derived from different hydrazines on the photographic properties of color negative material were studied. It was found that the DAR couplers examined may be used together with cyan coupler or yellow coupler in a color negative material to increase the photosensitivity; DAR couplers 4c and 8c that contained 1-trifluoroacetyl-2-(4-aminophenyl)hydrazine increased photosensitivity the most.