Methanesulfonyl chloride → 2-(Tert-butoxycarbonylamino)-2-(4-chlorophenyl)ethyl methanesulfonate

Participants

Reaction Conditions

Reaction Steps

Methanesulfonyl chloride (1.451 mL, 18.74 mmol) was added to tert-butyl 1-(4-chlorophenyl)-2-hydroxyethylcarbamate (4.63 g, 17.04 mmol) and N,N-diisopropylethylamine (6.23 mL, 35.78 mmol) in DCM (40 mL) cooled to 0° C. over a period of 5 minutes under nitrogen. The resulting solution was stirred at 20° C. for 2 hours. The reaction mixture was diluted with DCM (100 mL) and washed sequentially with water (100 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 10% EtOAc in DCM. Pure fractions were evaporated to dryness to afford 2-(tert-butoxycarbonylamino)-2-(4-chlorophenyl)ethyl methanesulfonate (3.12 g, 52.3%) as a white solid. 1H NMR (399.9 MHz, DMSO-d6) δ 1.39 (9H, s), 3.17 (3H, s), 4.22-4.28 (2H, m), 4.90 (1H, d), 7.40-7.46 (4H, m), 7.68 (1H, d). m/z (ESI+) (M−H)−=348; HPLC tR=2.32 min.

Provenance & Evidence