Although the high reactivity for replacement reactions of pyrimidines bearing a 2, 4-or 6- chloro group is well known, little has been done with halogen in the 5-position. Previously 5- bromouracil has been treated only with ammoniaa and di~ nethylamine,~~~~~ both reactions having been carried out in a sealed tube at 150-180. Moreover, Lythgoe5 and Johnsons both state that replacing chlorine or bromine in the 5-position by ammonia is a ...
