Synthesis of some amino‐substituted furanopyrimidines and styrylpyrimidines

5‐ p ‐Chlorophenyl‐6,6‐dimethyl‐5,6‐dihydro‐3 H ‐furano[2,3‐ d ]pyrimidine‐4‐one is readily converted to 4,6‐dichloro‐5‐β‐β‐dimethyl‐α‐ ( p ‐chlorostyryl)pyrimidine by warming in phosphorus oxychloride and acetic acid, behavior which is in strong contrast to that of the analogous 5‐phenyl derivative. The reaction provides a convenient source of 4‐amino‐6‐chloro‐5β,β‐dimethyl‐α‐ ( p ‐chlorostyryl)pyrimidines and 4,6‐diamino‐5‐β,β‐dimethyl‐α‐ ( p ‐chlorostyryl)pyrimidines, compounds of potential biological interest.