Synthesis of 1-(2-cyan)-phenyl-3-methyl-5-pyrazolone

1-(2-Cyan)-phenyl-3-methyl-5-pyrazolone is synthesized from 2-aminobenzonitrile by diazotization, reduction with stannous chloride in the presence of hydrochloric acid to give 2-cyanphenylhydrazine hydrochloride, which is subjected to neutralization with sodium methoxide and nucleophilic reaction with methyl acetoacetate. The method has been improved in the process of synthesis of 2-cyanphenylhydrazine hydrochloride and 1-(2-cyan)-phenyl-3-methyl-5-pyrazolone and the total yield can be increased to 79.4%.