Dimethyl Sulfide → (S)-tert-butyl 1-(4-acetyl-2-fluorophenyl)ethylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a round bottom flask containing (S)-tert-butyl(1-(2-fluoro-4-(prop-1-en-2-yl)phenyl)ethyl)carbamate (1.28 g, 4.58 mmol) was added DCM (23 mL). The homogenous solution was cooled to −70° C. in a acetone/dry ice bath. Ozone (g) was then gently bubbled through the solution for 25 min at which time the solution becomes pale blue in color. Dimethyl sulfide (1.02 mL, 13.8 mmol) was then added to the cold solution and mixture gradually allowed to warm to room temperature and stirred for 30 min. Reaction mixture was diluted with a water. Phases partitioned. Aqueous phase extracted with DCM. Organic phases combined, washed with brine, dried (Na2SO4), filtered and concentrated onto silica gel. Silica gel column chromatography (EtOAc/Heptane 0 to 60%) provided (S)-tert-butyl(1-(4-acetyl-2-fluorophenyl)ethyl)carbamate (296 mg, 1.05 mmol, 23% yield) as a colorless oil that crystallizes upon standing. 1H NMR (400 MHz, CDCl3) δ 1.38-1.49 (m, 12H) 2.59 (s, 3H) 5.01 (br. s., 1H) 7.40 (t, J=7.65 Hz, 1H) 7.62 (dd, J=11.20, 1.57 Hz, 1H) 7.71 (dd, J=7.95, 1.54 Hz, 1H). LCMS m/z 267.1 (carboxylic acid fragment+CH3CN) (M+H)+, Rt 0.89 min.

Provenance & Evidence