Preparation of pyrazoles and pyrazolines by the reaction of chlorocyclopropanols with hydrazines in the presence of crown ethers

Conclusions The reaction of gem-dichlorocyclopropanol with hydrazine and phenylhydrazine in the presence of crown ethers at 20C leads to the formation of the corresponding pyrazoles in yields up to 60%. Under analogous conditions, cis- and trans-chlorocyclopropanols and phenylhydrazine give N-phenylpyrazoline in 58% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 231–233, January, 1985.