Diethyl Ether → Tert-butyl 4-(trifluoromethoxy)phenylcarbamate

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Reaction Steps

A solution of 4-(trifluoromethoxy)phenyl isocyanate (9.75 g, 48.0 mMol) in THF (100 mL) was cooled to 0° C., and a 1.0 M THF solution of potassium tert-butoxide (53 mL, 53 mMol) was added dropwise. The mixture was allowed to warm to room temperature, and stirred for 7 hours. The solution was poured into a mixture of saturated ammonium chloride solution (200 mL), and diethyl ether (200 mL). Enough water was added to redissolve the ammonium chloride that had crashed out, the mixture was shaken in a separatory funnel, and the layers were separated. The organic phase was washed with saturated ammonium chloride (100 mL), water (100 mL), brine (100 mL), dried over sodium sulfate, and concentrated in-vacuo. The residue was purified over silica gel, eluting with 10%-20% ethyl acetate/heptane to yield 11.7 g of white solids as product. NMR (500 MHz, DMSO) δ 9.54 (s, 1H), 7.54 (d, 2H, J=7 Hz), 7.23 (d, 2H, J=8 Hz), 1.45 (s, 9H). Yield=88%.

Provenance & Evidence