Pyrimidine derivatives. IX . Synthesis of bromosubstituted 5‐nitro‐2,4(1 H ,3 H )‐pyrimidinedione derivatives

The following 5‐nitro‐2,4(1 H ,3 H )‐pyrimidinediones possessing bromo substituted side chains at the 1‐ and 6‐positions were prepared by bromination of 3,6‐dimethyl‐1‐(ω‐hydroxyalkyl)‐5‐nitro‐2,4(1 H ,3 H )‐pyrimidinediones 4a and 4b and its nitrates 2a and 2b . The three of mono‐bromo derivatives are: 1‐(ω‐acetoxyalkyl and ω‐hydroxyalkyl)‐6‐bromomethyl‐3‐methyl. 6a, 6b, 7a and 7b and 1‐(ω‐bromoalkyl)‐3,6‐dimethyl‐2,4(1 H ,3 H )‐ pyrimidinediones 8a and 8b . The one type dibromo derivatives are: 1‐(ω‐bromoalkyl)‐6‐bromomethyl‐3‐methyl‐2,4(1 H ,3 H )‐pyrimidinediones 5a and 5b .