Study on Synthesis of a Medicine Intermediate——Acetone Semicarbazone

Acetone semicarbazone was directly synthesized from hydrazine hydrate,urea and acetone.The effect of reaction temperature,reaction time,materials ratio and the amount of solvent on the synthesis was studied.The proper reaction conditions were as follows:the reaction temperature for hydrazine hydrate and urea was 100℃ and the reaction time was 7 h;the reaction temperature for semicarbazide and acetone is 55℃ and the reaction time was 2 h;the molar ratio of hydrazine hydrate∶urea∶acetone was 1∶1.6∶3.The yield of the product was 97.19%,and the purity of acetone semicarbazone was 98.5%.