Ammonia → 2-(1-Azetidin-3-yl-1H-pyrazol-5-yl)-4-(trifluoromethyl)phenol

Participants

Reaction Steps

Trifluoroacetic acid (4 mL) was added to a stirred solution of tert-butyl 3-{5-[2-hydroxy-5-(trifluoromethyl)phenyl]-1H-pyrazol-1-yl}azetidine-1-carboxylate, (Preparation 857, 375 mg, 0.001 mol) in dichloromethane (10 mL) under nitrogen and the solution was stirred for 3 hours. The pink solution was evaporated and the residue dissolved in methanol and then the solvents were removed in vacuo. This was repeated a further two times. The residue was then suspended in diethyl ether and the solvents removed in vacuo to give an off-white foam. The foam was dissolved in water and treated with aqueous ammonia solution (7.5 molar) until pH10 to give a white precipitate. The mixture was extracted with ethyl acetate (6×30 mL). The combined organic layers were washed with saturated aqueous sodium chloride solution (2×20 mL), dried over anhydrous sodium sulphate, filtered and the solvents removed in vacuo to give a solid. The solid was triturated with diethyl ether to give the title compound as a white solid (200 mg).

Provenance & Evidence