Methyl iodide → Tert-butyl 2-methyl-4-(trifluoromethyl)phenylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 4-(trifluoromethyl)phenylcarbamate (13.2 g, 50.5 mmol) at −78° C. was added tert-butyllithium (1.7 in pentane, 62.4 mL, 106 mmol). The reaction was allowed to gradually warm to −20° C. in the ice bath (ca. 1 h). The reaction was recooled to −78° C. and treated with iodomethane (3.79 mL, 61 mmol). The reaction was allowed to gradually warm to 0° C. and held there for 15 min. The reaction was quenched by addition of saturated ammonium chloride. The mixture was poured onto diethyl ether, washed with water (3×), then brine, dried over magnesium sulfate, and concentrated. The solid was triturated with pentane and filtered to collect a first crop (10.4 g, 75%). The mother liquor gave a second crop of solid (2.15 g, 15%) which was again collected by filtration. 1H-NMR (CDCl3, 500 MHz) δ 8.06 (d, J=8.2 Hz, 1H), 7.44 (d, J=8.9 Hz, 1H), 7.38 (s, 1H), 6.40 (bs, 1H), 2.28 (s, 3H), 1.53 (s, 9H); 13C-NMR (CDCl3, 126 MHz) δ 152.5, 139.8, 127.2 (q, J=3.8 Hz), 126.2, 125.0 (q, J=33 Hz), 124.4 (q, J=272 Hz), 124.2 (q, J=3.8 Hz), 119.5, 81.3, 28.4, 17.7. Mass spec.: 298.00 (MNa)+.

Provenance & Evidence