4-Aminophenol → N-(4-hydroxyphenyl)-1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carboxamide

Participants

Reaction Steps

To a solution of 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carboxylic acid (1.70 g, 7.35 mmol), HOAT (1.2 g, 8.82 mmol), and EDCI (1.68 g, 8.82 mmol) in DMF (40 mL) was added Et3N (2.6 mL, 18.38 mmol) drop wise. The solution was stirred at rt for 20 minutes, then a solution of 4-aminophenol (994 mg, 9.11 mmol) in DMF (6 mL) was added drop wise to the reaction system. The reaction was heated at 70° C. for 5 hours, then concentrated to 2 mL in vacuo, and diluted with water (50 mL). The precipitate was collected by filtration, washed with water (5 mL) and dried. The crude product was washed with DCM (20 mL) to give the title compound as a brown solid (2.02 g, 85%).

Provenance & Evidence