1,2-Dichloroethane → 3(S)-ethyl-prolyl-methionine isopropyl ester

Participants

Reaction Steps

N-(t-Butyloxycarbonyl)-pyrrolidin-2(S)-ylmethyl]3(S)-ethyl-proline (2.4 g, 0.008 mol), methionine isopropyl ester hydrochloride (2.21 g, 0.0097 mol), HOBT (1.49 g, 0.0097 mol) and EDC (1.86 g, 0.0097 mol) were dissolved in DMF (15 mL) at room temperature and treated with N-methylmorpholine (3 mL, 0.024 mol). The reaction mixture was stirred overnight at room temperature, then concentrated and partitioned between EtOAc and H2O. The organic layer was washed with aq satd NaHCO3 solution, brine, and dried (MgSO4). The crude product was chromatographed on a flash silica gel column eluting with hexane: EtOAc, 7:3 to give N-(t butyloxycarbonyl)-pyrrolidin-2(S)-ylmethyl]3(S)-ethyl-prolyl-methionine isopropyl ester.

Provenance & Evidence