Benzylhydrazine dihydrochloride → methyl 1-benzyl-3-methyl-1H-pyrazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of (Z)-methyl 2-((dimethylamino)methylene)-3-oxobutanoate (15.8 g, 92.5 mmol) in ethanol (50 mL) was added 1-benzylhydrazine dihydrochloride (18 g, 92.3 mmol). The resulting solution was stirred for 3.5 h at 80° C., then concentrated under reduced pressure. The residue was dissolved in 200 mL of ethyl acetate. The organic layer was washed with 1×40 mL of water and 2×40 mL of brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel chromatography with ethyl acetate/petroleum ether (1:4) as the eluent to furnish 12.4 g (58%) of the title compound as a yellow solid.

Provenance & Evidence