Hydrochloric Acid → 2-tert-Butoxycarbonylamino-3-(4-bromophenylsulfanyl)-propanoic acid methyl ester

Participants

Reaction Steps

Solution of 2-tert-Butoxycarbonylamino-3-methylsulfonylpropanoic acid methyl ester (0.86 g, 2.89 mmol) and 4-bromobenzenthiol (0.56 g, 2.89 mmol) in DMF (10 mL) was cooled to at 0° C. and treated with Cs2CO3 (1.1 g, 3.2 mmol). After stirring at room temperature for 2 h, the reaction was acidified with 5% HCl (15 mL) and diluted with ethyl acetate (25 mL). After separation, the aqueous layer was extracted with ethyl acetate (3×15 mL) and the combined organic layers were washed with sat. aq NaCl, dried over MgSO4, filtered, and concentrated. Purification by flash column chromatography (5% ethyl acetate in heptane) gave the desired product (857 mg, 76%) as a white solid. 1H NMR (CDCl3), δ 7.40 (d, J=9 Hz, 2H), 7.27 (d, J=9, 2H), 5.30 (d, J=7 Hz, 1H), 4.56 (m, 1H), 3.59 (s, 3H), 3.35 (ddd, J=7, 7, 12 Hz, 2H), 1.47 (s, 9H).

Provenance & Evidence