Abstract Bromine reacts with 6-methyldihydropyrimidine-2-ones or 5-carbethoxy-6- methyldihydropyrimidine-2-ones to yield 6-bromomethyldihydropyrimidine-2-ones. 5- carbethoxy-6-bromomethyldihydropyrimidine-2-ones on heating split off ethyl bromide to give 6-hydroxymethyldihydropyrimidine-2-one-5-carboxylic acid lactones. Chlorine is added to the double bond of 5-carbethoxy-6-methyldihydropyrimidine-2-ones.
