1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → 1-tert-butyl-5-(4-fluorophenyl)-1H-pyrazole-4-carboxamide

Participants

Reaction Steps

A solution of the compound (16.87 g, 64.32 mmol) obtained in step 2, WSC (16.03 g, 83.62 mmol), HOBt (11.30 g, 83.62 mmol), TEA (11.65 mL, 83.62 mmol) and ammonium chloride (4.47 g, 83.62 mmol) in DMF (200 mL) was stirred at room temperature for 2 days. Water was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and saturated brine and dried, and the solvent was evaporated under reduced pressure. The obtained residue was purified by silica gel column chromatography (solvent gradient; 5→85% ethyl acetate/hexane) to give 1-tert-butyl-5-(4-fluorophenyl)-1H-pyrazole-4-carboxamide (14.72 g, 56.3 mmol, 88%) as a white powder.

Provenance & Evidence