Dichloromethane → HCID 66813097, compound

Participants

Reaction Steps

To a mixture of the crude (R)-2-Amino-benzo[b]thiophen-2-yl-N-methyl-propionamide hydrochloride (600 mg, ca. 2.0 mmol), triethylamine (0.6 mL, 4.0 mmol), and dichloromethane (20 mL) was added carbonyl diimidazole (2.44 g, 15 mmol). The reaction mixture was stirred overnight at room temperature under argon and then diluted with 200 mL of ethyl acetate. The organic solution was washed with 1N HCl (2×50 mL) and brine (60 mL), dried over anhydrous MgSO4, filtered and concentrated. The residue was purified by column chromatography on silica gel using hexane/ethyl acetate (50:50) to give 370 mg of 5-benzo[b]thiophen-2-ylmethyl-3-methyl-imidazolidine-2,4-dione as a white solid (71% overall yield). It is notable that the product was racemic indicative that racemization had occurred under these reaction conditions. (893-39) 1H NMR (500 MHz, CDCl3): δ 7.89 (1H, dd, J=1.5, 7.5 Hz), 7.78 (1H, dd, J=1.0, 7.0 Hz), 7.41 (2H, m), 7.27-7.24 (1H, m), 5.46 (1H, s), 4.33 (1H, ddd, J=1.0, 3.5, 9.5 Hz), 3.60 (1H, ddd, J=1.0, 3.5, 14.5 Hz), 3.03 (1H, dd, J=9.5, 14.5 Hz), 3.02 (3H, s).

Provenance & Evidence