The synthesis of 6,7‐dihydro‐5 H ‐pyrrolo[3,4‐ d ]pyrimidines. II. 4‐Hydroxy, 4‐mercapto, 2‐amino‐4‐hydroxy and 2,4‐dihydroxy derivatives

Several new types of compounds in the 6,7‐dihydro‐5 H ‐pyrrolo[3,4‐ d ]pyrimidine series have been prepared. Included are a 6‐acyl derivative unsubstituted in the pyrimidine ring, as well as 4‐hydroxy, 4‐mercapto, 2‐amino‐4‐hydroxy and 2,4‐dihydroxy derivatives. These products were derived directly or indirectly from 4‐cyano‐ or 4‐carbethoxy‐1‐acyl‐3‐amino‐3‐pyrroline intermediates. 3‐Hydroxy, 3‐amino, and 3‐thioformylamino‐1‐acyl‐3‐pyrroline‐4‐thiocarboxamides have been obtained and the 3‐thioformylamino derivatives shown to undergo base‐catalyzed cyclization to close a 4‐mercaptopyrimidine ring.