Pyrimidine derivatives. VI . Synthesis of mono‐, di‐, tri‐, and tetrabromo‐substituted pyrimidine derivatives

The following bromo‐2,4(1 H ,3 H )‐pyrimidinediones possessing a bromo substituent at the 5‐position and side chains at the 1‐ and 6‐positions were prepared. The three types of mono‐bromo derivatives are: 1‐(bromoalkyl)‐3,6‐dimethyl‐ 3a‐d , 5‐bromo‐3,6‐dimethyl‐1‐(hydroxyalkyl)‐ 4a‐d , and 1‐(acetoxyalkyl)‐5‐bromo‐3,6‐dimethyl‐2,4(1 H ,3 H )‐pyrimidinediones 11a‐d . The three types of dibromo derivatives are: 5‐bromo‐1‐(bromoalkyl)‐3,6‐dimethyl‐ Sa‐d , 1‐(acetoxyalkyl)‐5‐bromo‐6‐bromomethyl‐ 8a, 8c , and 8d , and 5‐bromo‐6‐bromomethyl 1‐(hydroxyalkyl)‐2,4(1 H ,3 H )‐pyrimidinediones 9a, 9c , and 9d . Likewise one group of tribromo and one group of tetrabromo derivatives are: 5‐bromo‐1‐(bromoalkyl)‐6‐bromomethyl ‐7a‐d and 5‐bromo‐1‐(bromoalkyl)‐6‐dibromomethyl‐2,4(1 H ,3 H )‐pyrimidinediones 6a‐d .