Synthesis of optically active imidazo[1,2-a]pyrimidin-3(2H)-ones

The reactions of 2-chloro-4-(substituted amino)-6-methyl-5-nitropyrimidine 1 with (L)-α-amino acids gave substituted derivatives 3, which were converted to optically active imidazo[1,2-a]pyrimidines 4 by treatment with either phosphorus oxychloride or polyphosphoric acid.