4-Toluenesulfonyl chloride → tert-butyl N-{2-[(4-methylbenzenesulfonyl)oxy]ethyl}carbamate

Participants

Reaction Conditions

Reaction Steps

A solution of p-toluenesulfonyl chloride (28.40 g, 148 mmol) in dichloromethane (100 mL) was added dropwise over 30 minutes at 0° C. to a mixture of tert-butyl N-(2-hydroxyethyl)carbamate (20 g, 120 mmol), triethylamine (18.80 g, 186 mmol) and trimethylammonium chloride (1.18 g, 12.4 mmol) in dichloromethane (120 mL). The mixture was stirred at 0° C. for 1 hour then filtered, washing with dichloromethane (100 mL). The filtrate was washed with 10% citric acid (3×100 mL) and brine (100 mL). The organic layer was dried with magnesium sulfate and then filtered. The filtrate was concentrated under reduced pressure to give an oil. The oil was dissolved in ethyl acetate (40 mL) and then iso-hexane (160 mL) was added slowly. The resultant slurry was stirred at room temperature for 17 hours and then filtered. The collected solid was washed with iso-hexane (240 mL) to yield the sub-title compound as a colourless powder (25 g, 64%).

Provenance & Evidence