The Mechanism of Bromination of 2(1H)-Pyrimidinone, its N-Methyl and N,N′-Dimethyl Derivatives in Aqueous Acidic Solution

Abstract

Rates of bromination at the 5-positions of the title compounds have been measured in aqueous sulfuric acid solutions. The reaction involves a rapid irreversible formation of a 5-bromo-4,6-dihydroxy-hexahydro-2-oxopyrimidine which undergoes slow acid-catalyzed conversion to the corresponding 5-bromopyrimidinone. If excess bromine is present the latter product reacts further to produce a 5,5-dibromo-4,6-dihydroxyhexahydropyrimidine.