Diisopropylethylamine → (S)-2-[4-(3-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-3-cyclohexyl-propionic acid methyl ester

Participants

Reaction Steps

To a stirred solution of (S)-2-amino-3-cyclohexyl-propionic acid methyl ester (786 mg, 0.004 mol) in N,N-dimethylformamide (10 mL) was added N,N-diisopropylethylamine (2.58 g, 0.020 mol) slowly at room temperature, under nitrogen. The resulting mixture was stirred for 5 min and then treated with (E)-4-bromo-3-(3-chloro-phenoxy)-but-2-enoic acid ethyl ester (1.30 g, 0.004 mol) and the reaction mixture was heated at 110° C.-120° C. for 16 h. After this time, ice water was added and the resulting mixture was extracted with ethyl acetate. The combined organic layers were washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate and concentrated in vacuo. Purification by flash column chromatography (silica gel (100-200 mesh)) afforded (S)-2-[4-(3-chloro-phenoxy)-2-oxo-2,5-dihydro-pyrrol-1-yl]-3-cyclohexyl-propionic acid methyl ester (530 mg, 33%) as a yellow oil.

Provenance & Evidence