Methane → 3-Amino-5-(4-benzyl-1-piperazinyl)-4-pyrazolecarbonitrile

Participants

Reaction Conditions

Reaction Steps

A mixture of 4.25 g (0.025 moles) of [bis(methylthio)methylene]malonnitrile [K. A. Jensen and L. Henriksen, Acta Chem. Scand. 22 (4) 1107 (1968)] and 4.7 g (0.025 moles) of 1-benzylpiperazine in 100 ml of acetonitrile was stirred at reflux for 5 hours with evolution of methanethiol. Then 1.31 g (0.025 moles) of hydrazine hydrate was added and the solution was stirred at reflux for 16 hours, again with evolution of methanethiol. The reaction mixture was clarified while hot with activated charcoal and filtered through diatomaceous earth. The filtrate was cooled at -10° C. and a white precipitate developed. The precipitate was collected by filtration, washed with 50 ml of cold acetonitrile, air dried, then dried in vacuo at 60° C. and gave 4.5 g of crude product. The material was recrystallized from 150 ml of 2-propanol cooled at -10° C. and gave 2.8 g of the desired product as a white solid, mp 157°-158° C.

Provenance & Evidence