2,2,2-Trifluoroethylhydrazine → 3,3a,4,5,6,7-hexahydro-3-phenyl-7-(phenylmethylene)-2-(2,2,2-trifluoroethyl)-2H-pyrazolo[4,3-c]-pyridine, monohydrochloride

Participants

Reaction Steps

3,5-Dibenzylidene-4-piperidone, hydrochloride (10.0g) is reacted with 5.8 g of 70% aqueous 2,2,2-trifluoroethylhydrazine in 220 ml of methanol at reflux for 4 hours. Evaporation of the methanol on a rotary evaporator leaves 14 g of a foamy residue which crystallizes when triturated with 50 ml of boiling acetonitrile to yield (after cooling for about 16 hours) 10.3 g of material, melting point 206°-209° C (sintering at 195° C). Crystallization from 80 ml of ethanol yields 6.7 g of product, melting point 207°-209° C, sintering at 196° C.

Provenance & Evidence