Ultrasound Assisted Synthesis Of Pyrazolone Derivatives

ABSTRACT The diazonium salt of 4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol- 2-one (4-aminoantipyrine) was coupled with ethylacetoacetate and ethyl benzoylacetate to give the corresponding diazo compounds under basic media. These products were allowed to react with hydrazine hydrate and phenylhydrazine under Ultrasound method to give pyrazolone derivatives (I) in high yields.