Pyrimidine derivatives. VII . Nucleophilic reactions of 5‐bromo‐1‐(bromoalkyl)‐6‐bromomethyl‐2,4(1 H ,3 H )‐pyrimidinediones

The reactions of 1‐(bromoalkyl)‐5‐bromo‐6‐bromomethyl‐3‐methyl‐2,4(1 H ,3 H )‐pyrimidinedione (1) with several nucleophiles were examined as follows: by reaction with sodium methoxide, 6‐(bismethoxy)methyl‐5‐debrominated derivatives 2, 3 , and 4 were prepared; the corresponding di‐substituted compounds (side chains in 1‐and 6‐positions) 5, 6, 7 , and 9 were obtained by treatment with silver nitrate, silver acetate, potassium thiocyanate, and potassium thioacetate; the reaction with thioacetamide and iso ‐butylamine gave bicyclic compounds [1,4]thiazino[4,3‐c]‐ 11 , pyrazino[1,2‐ c ]‐ 12 , and [1,4]diazepino[1,2‐ c ]pyrimidinedione 13 , respectively; pyrrolidine, morpholine, and sodium azide afforded the corresponding 6‐substituted compounds 14, 15 , and 16 .