4-Fluorophenylhydrazine hydrochloride → 4-[5-dimethoxymethyl-2-(4-fluoro-phenyl)-2H-pyrazol-3-yl]-pyridine

Participants

Reaction Steps

A stirred solution of 4,4-dimethoxy-1-pyridin-4-yl-butane-1,3-dione (20 g, Reference Example 2) in ethanol (500 ml) was treated with 4-fluorophenylhydrazine hydrochloride (29 g). The mixture was refluxed for 0.5 hour then evaporated. The residual yellow oil was subjected to flash chromatography on silica eluting with a mixture of methanol and dichloromethane (99:1, v/v) to give the title compound as a brown oil (2.7 g). MS: 314 [MH]+. RF=0.27 (ethyl acetate, determined by thin layer chromatography on silica).

Provenance & Evidence