Polyfunctionalized pyrimidines based on 1,2,4-triketones

An approach was developed for the synthesis of polyfunctionalized pyrimidines based on analogs of 1,2,4-triketones. Acetal-substituted β-diketones are involved in the condensation with amidines in the presence of an excess of (EtO) 3 B/Et 3 N in acetonitrile. The conditions of the acid hydrolysis of acetal-containing pyrimidines were found to depend on the nature of substituents in diazine. The use of 1,2,4-triketone in the condensation with amidine allows the synthesis of acetylpyrimidine in one step.