Sodium Hydroxide → 2,2,2-Trichloroethyl (3-tert-butyl-1-methyl-1H-pyrazol-5-yl)carbamate

Participants

Reaction Steps

To a cooled (10° C.) solution of 5-tert-butyl-2-methyl-2H-pyrazol-3-ylamine (3.75 g, 24.5 mmol) and NaOH (1.5 g in 20 mL water) in ethyl acetate (45 mL) was added 2,2,2-trichloroethyl chloroformate (7.52 g, 35.5 mmol) over 5 minutes. The reaction mixture was warmed to room temperature and stirred for 2 hours. The mixture was diluted with ethyl acetate and the layers separated. The organic layer was washed with water, brine, dried over MgSO4, and concentrated under reduced pressure. The residue was diluted with ethyl acetate/dichloromethane and treated with aminomethyl silica (10 g) for 1 hour. The mixture was filtered and the filtrated concentrated under reduced pressure to provide the product.

Provenance & Evidence