SYNTHESIS OF SOME SULFUR-CONTAINING PYRIDO[1,2-A]PYRIMIDINES

4-Methylthiopyrido[1,2-a]pyrimidin-2-one and 2-hydroxypyrido[1,2-a]pyr imidine-thione derivatives were synthesized by the addition of N-(4-R- pyrid-2-yl)acetoacetamides (R = H, Me) to CS2 under phase-transfer con ditions followed by the alkylation of the reaction products with Mel. Tile molecular structure of 3-acetyl-4-methylthiopyrido[1,2-a]pyrimidi n-2-one is established by X-ray analysis.