Hydrazine hydrate (1:1) → 4-(1-benzyl-1H-imidazol-2-ylmethyl)-3,5-diethyl-1H-pyrazole

Participants

Reaction Steps

To a solution of 140 mg (0.47 mmol) 4-(1-benzyl-1H-imidazol-2-ylmethyl)-heptane-3,5-dione in 1.5 ml ethanol was added a solution of 24 mg (0.48 mmol) hydrazine monohydrate in 0.5 ml ethanol and the mixture heated to reflux for 10 min. The reaction mixture was evaporated under reduced pressure, the residue dissolved in 1N aqueous HCl solution and extracted three times with t-butyl methyl ether. The aqueous phase was adjusted to pH 12 and extracted three times with t-butyl methyl ether, the combined extracts washed with brine, dried over sodium sulfate, filtered and evaporated. Purification of the residue by flash-chromatography on silica gel with ethyl acetate as eluent provided 4-(1-benzyl-1H-imidazol-2-ylmethyl)-3,5-diethyl-1H-pyrazole as colourless viscous oil: MS (ISP): 295.3 ((M+H)+.).

Provenance & Evidence