Hydrochloric Acid → tert-butyl N-(2-oxoethyl)carbamate

To a mixed solution of tert-butyl (2-hydroxyethyl)carbamate (10.0 g) in dimethyl sulfoxide (50 mL) and triethylamine (12.3 g) was added sulfur trioxide pyridine complex (15.0 g) under ice-cooling, and the mixture was stirred for 1 hr. The reaction mixture was further stirred at room temperature for 3 hr, 1 mol/L hydrochloric acid was added, and the mixture was extracted with ethyl acetate. The separated aqueous layer was extracted again with ethyl acetate. The combined organic layers were washed with saturated brine, dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent:hexane-ethyl acetate=17:3→13:7) to give the title compound as a pale-yellow oil (yield 6.50 g, 66%). 1H-NMR (CDCl3) δ: 1.46 (9H, s), 4.08 (2H, d, J=4.5 Hz), 5.19 (1H, brs), 9.66 (1H, s).

1. temperaturecooling
2. stirringThe reaction mixture was further stirred at room temperature for 3 hr
3. extractionthe mixture was extracted with ethyl acetate
4. extractionThe separated aqueous layer was extracted again with ethyl acetate
5. washThe combined organic layers were washed with saturated brine
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography (eluent:hexane-ethyl acetate=17:3→13:7)

ORD record

ord-4ade4f4eae1241a98644b34fe4b85bef

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08592597B2