ISMRa ,URA480 CNRS,Universite' de Caen, F I4050 Caen cedex, France. ... ABSTRACT: 3-Methyl- 1 -phenyl-5-pyrazolone (1) and arylcarboxyaldehydes (2) were condensated to 1 -phenyl-3-methyl-4-(arylmethylene)-S-pyrazoIoiie ... The derivatives of the pyrazolone are important class of antipyretic and analgesic compounds ( antipyrine, amidopyrine, phenylbutazolone). l-Phenyl-3-methyl-4- (arylmethylene)-5-pyrazolones (3) are useful intermediate in ...