Studies on Pyrimidinylpyrazoles. I. Syntheses of 1-and 2-Pyrimidinyl-3-methylpyrazolin-5-one Derivatives

In order to find new analgesics and anti-inflammatories, 1-and 2-pyrimidinyl-3-methylpyrazolin-5-one derivatives (III and VII) were synthesized from hydrazinopyrimidines (I) and ethyl acetoacetate or ketene dimer, and then methylated to afford 1-and 2-pyrimidinyl-3-methyl-5-methoxypyrazoles (IV and VIII), 1-pyrimidinyl-2, 3-dimethylpyrazolin-5-ones (V), and 2-pyrimidinyl-1, 3-dimethylpyrazolin-5-ones (IX). Physical properties of these derivatives were also described.