4-Toluenesulfonyl chloride → (S)-2-(Methylamino)-2-oxo-1-phenylethyl 4-methylbenzenesulfonate

Participants

Reaction Steps

TsCl (4.75 g, 25 mmol, 1.0 eq) was added portion-wise at rt to a solution of 37 (4.13 g, 25 mmol, 1.0 eq) and DIPEA (3.22 g, 4.4 mL, 25 mmol, 1.0 eq) in dichloromethane (100 mL). The reaction mixture was stirred at rt for 5 h, then was concentrated under reduced pressure to give an oil. The crude oil was dissolved in ethyl acetate (150 mL), and the solution was washed sequentially with water (100 mL), saturated sodium bicarbonate solution (2×75 mL) and brine (75 mL). The organic solution was dried over sodium sulfate and filtered. The filtrate was concentrated under reduced pressure to near dryness. The solid was triturated with methyl t-butyl ether (100 mL), filtered and dried to give 4.89 g (61%) of 38 as a white solid.

Provenance & Evidence