Diisopropylethylamine → 3,5-dichlorophenyl-sulfonyl-L-proline methyl ester

Participants

Reaction Steps

To a mixture of (L)-proline, methyl ester hydrochloride (838 mg, 5.06 mmol) in CH2Cl2 (25 mL) at 0° C. were added DIPEA (2.64 mL, 15.2 mmol) and a solution of 3,5-dichlorobenzenesulfonyl chloride (1.49 g, 6.07 mmol) in CH2Cl2 (5 mL). The cooling bath was removed, and the mixture was stirred overnight at rt. It was then diluted with CH2Cl2, washed with 1N hydrochloric acid, saturated NaHCO3, saturated brine solution, dried over anhydrous Na2SO4, and rotoevaporated. The product was purified by flash column chromatography on silica gel eluted with 10% acetone in hexanes to yield N-(3,5-dichlorobenzenesulfonyl)-(L)-proline, methyl ester; yield 1.49 g.

Provenance & Evidence