Use of Yellow couplers of the indolo [3,2-B] guinoline type in a colo+E,uml u+EE r photographic development process

摘要

Compounds of the formula I are suitable as photographic yellow couplers <IMAGE> (I) In formula I, Z1, Z2mean residues to complete 5-, 6- or 7-membered rings of an aromatic or heteroaromatic nature; these rings may be substituted with substituents R1, R2, R3 and R4; X means H or a substituent which is released under chromogenic development conditions.