Hydrochloric Acid → 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-methylbutyric acid benzyl ester

Participants

Reaction Steps

To a solution of D-valine benzyl ester (4 g, 19.3 mmol) and trimethylsilylcyanide (7.2 mL, 57.9 mmol) in acetonitrile (40 mL) was added 4-methoxy-2,3,6-trimethylbenzenesulfonyl chloride (4.8 g, 19.3 mmol). After 3 h, the reaction mixture was diluted with ethyl acetate (100 mL) and transferred to a separatory funnel. Aqueous hydrochloric acid (120 mL, 2.5%) was added and the organic layer was separated and washed with 5% sodium bicarbonate and brine and then dried over magnesium sulfate. The organics were removed in vacuo to give 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-methylbutyric acid benzyl ester (8 g) as a brown oil.

Provenance & Evidence