Citric Acid → N-(6-acetoxy naphthalene-2-sulfonyl)-D-valine tert-butyl ester

Participants

Reaction Steps

D-valine tert-butyl ester (6.24 g, 35.9 mmol), 6-acetoxy naphthalene-2-sulfonyl chloride (10.2 g, 35.9 mmol) and triethylamine (12.5 mL, 89.7 mmol) are stirred in dioxane-water (1:1, 243 mL) at ambient temperature for 2 hours. The reaction mixture is acidified with a solution of aqueous citric acid (10% w/w, 800 mL). The precipitate is collected by filtration affording product as pale yellow crystals (10.2 g, 68% yield). LCMS (m/z): (439.28; M+18, 420.24; M−1).

Provenance & Evidence