4-Methoxybenzenesulfonyl chloride → N-[4-methoxybenzenesulfonyl]-(D)-asparagine

Participants

Reaction Conditions

Reaction Steps

D-asparagine (13.2 g, 100.0 mmol) is dissolved in dioxane (75.0 mL) and water (125.0 mL), triethylamine (21.0 mL, 150.0 mmol) is added, and the solution is cooled to 0° C. To this solution is added 4-methoxybenzenesulfonyl chloride (22.7 g, 110.0 mmol) over 10 minutes. The reaction is warmed to room temperature and stirred for 3 days. The precipitate is then filtered off, the filtrate is acidified to pH=~4, and extracted well with ethyl acetate. A first crop of pure product precipitates from the ethyl acetate and is collected by filtration. A second crop is obtained by evaporating off the ethyl acetate, and rinsing the solid obtained with water to remove inorganic salts. The two crops are combined to give N-[4-methoxybenzenesulfonyl]-(D)-asparagine.

Provenance & Evidence