TETRA HYDRO PYRINIDINE - 2,4 DIONES

摘要

There are described novel compounds which are represented by the formula wherein R is A is sulfur or selenium; X represents the nonmetallic atoms necessary to form a nucleus which completes a five or six membered heterocyclic moiety; R1 is H or lower alkyl; R2 is H or a hydrolyzable group; and R3 is H, alkyl or a hydrolyzable group. The compounds are useful in photographic applications and provide controlled release of a photographically useful material during processing of photographic elements with an aqueous alkaline processing composition.