Diisopropylethylamine → tert-butyl[4-(2-fluorophenyl)-2-methyl-1H-imidazol-1-yl]carbamate

Participants

Reaction Steps

Compound C1 (11.4 g, 65.8 mmol), 2-bromo-1-(2-fluorophenyl)ethanone (13.0 g, 59.9 mmol) and N,N-diisopropylethylamine (23.0 mL, 132 mmol) were combined in a mixture of acetonitrile (100 mL) and 2-methyltetrahydrofuran (300 mL) and heated at reflux for 18 hours. After cooling, the reaction mixture was concentrated in vacuo; the residue was mixed with ethyl acetate, then washed sequentially with saturated aqueous ammonium chloride solution and with saturated aqueous sodium bicarbonate solution. The combined aqueous layers were extracted with ethyl acetate, and the combined organic layers were dried over magnesium sulfate, filtered, and concentrated under reduced pressure to provide the product as a pale brown foam. Yield: 18.1 g, assumed quantitative. LCMS m/z 292.4 [M+H]+. 1H NMR (500 MHz, CDCl3), presumed to be a mixture of rotamers: δ 8.15 (v br s, 1H), 8.03-8.07 (m, 1H), 7.30 and 7.31 (2 s, 1H), 7.13-7.20 (m, 2H), 7.02-7.08 (m, 1H), 2.31 (s, 3H), 1.49 (br s, 9H).

Provenance & Evidence