Diisopropylethylamine → benzyl N-(2-oxoethyl)carbamate

Participants

Reaction Steps

To a stirred solution of (2-hydroxyethyl)-carbamic acid benzyl ester (1.0 g, 5.1 mmol) and N,N-diisopropylethylamine (1.78 mL, 10.2 mmol) in dichloromethane (15 mL) was added a solution of sulfur trioxide-pyridine complex (1.63 g, 10.2 mmol) in dimethyl sulfoxide (15 mL) at −20° C. After 1 h, the reaction was warmed to room temperature, diluted with dichloromethane (50 mL) and washed with 1.0 N HCl (50 mL) and brine. The organics were separated, dried with anhydrous sodium sulfate, filtered, and concentrated. The crude material was purified by silica gel chromatography, eluting with ethyl acetate in hexanes (0% to 80% gradient) to give the title product (810 mg, 82%). 1H NMR (CDCl3, 300 MHz) δ (ppm): 9.5 (s, 1H) 7.4-7.2 (m, 5H), 5.1 (s, 2H), 3.9 (d, J=5.8 Hz, 2H), 2.9-3.3 (br, 1H).

Provenance & Evidence