Trifluoroacetic acid → Ethyl 6-amino-5-bromo-2-(cyclopent-1-en-1-yl)benzofuran-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

TFA (1.5 mL) was added into a solution of ethyl 6-amino-5-bromo-2-(1-hydroxycyclopentyl)benzofuran-3-carboxylate (2.9 g, 7.89 mmol) in DCM (30 mL), then the mixture was stirred at 25° C. for 12 hours. The reaction mixture was poured into ice water, adjusted to pH=7 with NaHCO3 (a.q.), then the residue was extracted with DCM (50 mL*3), dried over Na2SO4, and concentrated to give the product of ethyl 6-amino-5-bromo-2-(cyclopent-1-en-1-yl)benzofuran-3-carboxylate (2.6 g, yield: 94%). 1H-NMR (CDCl3, 400 MHz) δ 7.99 (s, 1H), 7.11 (t, J=7.2 Hz, 1H), 6.83 (s, 1H), 4.43 (q, J=7.2 Hz, 2H), 2.86˜2.91 (m, 2H), 2.59˜2.63 (m, 2H), 2.01 (t, J=8.0 Hz, 2H), 1.46 (t, J=3.2 Hz, 3H). MS (M+H)+: 350/352.

Provenance & Evidence