Diisopropylethylamine → benzyl N-(2-oxoethyl)carbamate

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).

1. washwashed with 1.0 N HCl (50 mL) and brine
2. customThe organics were separated
3. dry with materialdried with anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customThe crude material was purified by silica gel chromatography
7. washeluting with ethyl acetate in hexanes (0% to 80% gradient)

ORD record

ord-735a9595b6ec46faa52f5ad0a6212f4f

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08518966B2