Hydrochloric Acid → HCID 11782271, compound

Participants

Reaction Steps

A solution of 4-hydroxy-N-tert-butoxycarbonyl-proline methyl ester (5.89 g, 24 mmol) and triethylamine (4 mL, 28.8 mmol) in dichloromethane (80 mL) was cooled to 0° C. and treated with methylsulfonyl chloride (2.1 mL). After stirring an additional 2 h, the reaction mixture was acidified with 2% HCl (20 mL) and extracted with dichloromethane (3×20 mL). The combined organic layers were washed successively with sat. aq NaHCO3, and sat. aq NaCl, dried over MgSO4 and concentrated. Purification by flash column chromatography (5% ethyl acetate in heptane) gave 4-methylsulfonyloxy-N-tert-butoxycarbonyl-proline methyl ester. 1H NMR (CDCl3), 5.25 (m, 1H), 4.41 (m, 1H), 3.78 (m, 5H), 3.06 (s, 3H), 2.61 (m, 1H), 2.22 (m, 1H), 1.46 (s, 9H).

Provenance & Evidence