Ethanol → 1-phenyl-3-(1-piperazinyl)-1H-indazole

Participants

Reaction Steps

A stirred solution of 6.4 g of 4-(1-phenyl-1H-indazol-3-yl)-1-piperazine carboxylic acid ethyl ester, 6.1 g of potassium hydroxide in 60 ml of water, and 120 ml of ethanol was refluxed under nitrogen for 32 hours. The reaction mixture was concentrated in vacuo, diluted with water, and extracted with diethyl ether. The extract was washed with water and then with brine, dried over anhydrous magnesium sulfate, and concentrated to give 4.4 g of 1-phenyl-3-(1-piperazinyl)-1H-indazole as a solid. The solid was dissolved in ethyl acetate/diethyl ether and treated with ethereal hydrogen chloride to precipitate the hydrochloride salt. Recrystallization from methanol/diethyl ether gave 2.5 g (45%) of 1-phenyl-3-(1-piperazinyl-1H-indazole hydrochloride, mp 265°-267°.

Provenance & Evidence