Acetyl chloride → (S)-3-(4-acetylamino-2-benzyloxy-benzenesulfonylamino)-4,4-diethoxy-butyric acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 11.2 g (21.7 mmol) (S)-3-(4-amino-2-benzyloxy-benzenesulfonylamino)-4,4-diethoxy-butyric acid tert-butyl ester and 50 mL dichloromethane and cooled to 0° C. in an ice/water bath. 3.2 mL (25 mmol) N-ethylmorpholine was added, followed by dropwise addition of 1.71 mL (24 mmol) acetyl chloride. After 10 min reaction time, TLC analysis showed complete reaction. The mixture was transferred to a separatory funnel and washed with 50 mL water, 50 mL brine, dried over anhydrous magnesium sulfate, filtered and concentrated to give 12 g (21.8 mmol, 100%) of (S)-3-(4-acetylamino-2-benzyloxy-benzenesulfonylamino)-4,4-diethoxy-butyric acid tert-butyl ester as a brown oil. MS (APCI) m/z 549.1 (M−1), 459.1 (M-CH2Ph).

Provenance & Evidence