Reactions of 3-hydroxytetrahydropyrimidin-4-ones with electrophilic reagents

The reactions of nonsubstituted or a-aryl-substituted 3-hydroxytetrahydropy rimidin-4-ones (HTHP) with carboxylic acid chlorides, tosyl chloride, or ar yl isocyanates afford mainly N,O-diacylated, N,O-ditosylated, or N,O-diaryl carbamoylated HTHP, respectively. N,O-Diacylated HTHP are also formed in th e reactions of acid chlorides with Schiffs bases based on beta-aminopropion ohydroxamic acid. N-Acylated HTHP can be obtained by treating N,O-diacylate d HTHP with ammonia. The reactions of 2,2-dialkyl(alkylene)-substituted HTH P with acid chlorides or phenyl isocyanate give N,O-diacylated or N,O-diphe nyl-carbamoylated beta-aminopropionohydroxamic acid, respectively.