Blocked pyrazolone magenta dye-forming couplers

Abstract

Novel 5-pyrazolone magenta dye-forming couplers are blocked with a coupler moiety which yields an alkali-soluble or colorless reaction product. The coupler moiety is joined via its coupling position to the enol oxygen of the 5-pyrazolone and is displaced therefrom during processing as a result of reaction by means of oxidized color developing agent to thereby activate the 5-pyrazolone coupler. These couplers have good reactivity and good resistance to aerial contaminants, such as formaldehyde, and can be incorporated in photographic emulsions and elements.

Description