Hydrochloric Acid → Ethyl 5-bromo-2-(cyclopent-1-en-1-yl)-6-(methylsulfonamido)benzofuran-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 6-amino-5-bromo-2-(cyclopent-1-en-1-yl)benzofuran-3-carboxylate (3.63 g, 10.37 mmol) and pyridine (2.46 g, 31.1 mmol) in DCM (30 mL) was added dropwise methanesulfonyl chloride (2.37 g, 20.7 mmol) at 0° C., then the mixture was stirred at 25° C. overnight. 10% HCl(a.q.) was added, then the mixture was extracted with DCM (50 mL*3), dried over Na2SO4, and concentrated to give the product of ethyl 5-bromo-2-(cyclopent-1-en-1-yl)-6-(methylsulfonamido)benzofuran-3-carboxylate (4.3 g, yield: 96%). 1H-NMR (CDCl3, 400 MHz) δ 8.19 (s, 1H), 7.80 (s, 1H), 7.22 (t, J=2.0 Hz, 1H), 6.84 (s, 1H), 4.45 (q, J=7.2 Hz, 2H), 2.99 (s, 3H), 2.89˜2.94 (m, 2H), 2.62˜2.67 (m, 2H), 2.06 (t, J=7.6 Hz, 2H), 1.47 (t, J=7.2 Hz, 3H). MS (M+H)+: 428/430.

Provenance & Evidence