Dimethylformamide dimethyl acetal → ethyl 1-tert-butyl-5-(4-fluorophenyl)-1H-pyrazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl 3-(4-fluorophenyl)-3-oxopropanoate (19.8 g, 94.20 mmol) and DMFDMA (13.76 mL, 103.61 mmol) in toluene (150 mL) was stirred at 100° C. for 14 hr, and concentrated under reduced pressure. The residue was dissolved in ethanol (150 ml), tert-butylhydrazine hydrochloride (11.74 g, 94.20 mmol) and TEA (14.44 mL, 103.61 mmol) were added thereto. The reaction mixture was stirred at 80° C. for 3 hr, and concentrated under reduced pressure. The residue was dissolved in ethyl acetate, and the solution was washed with water and saturated brine and dried, and the solvent was evaporated under reduced pressure to give ethyl 1-tert-butyl-5-(4-fluorophenyl)-1H-pyrazole-4-carboxylate (18.67 g, 64.3 mmol, 68.3%) as a white powder.

Provenance & Evidence