反应详情

To a solution of 6-amino-5-bromo-2-cyclopropylbenzofuran-3-carboxylic acid (6.5 g, 22 mmol) in dry DMF (500 mL) were added EDCI (2.98 g, 2.4 mmol) and HOBT (6.33 g, 3.6 mmol). The reaction mixture was stirred at room temperature for 2 h, and then Et3N (20 mL) and MeNH2.HCl (7.3 g, 110 mmol) were added to the reaction mixture. After stirring for another 2 hours, the reaction mixture was concentrated in vacuum and Na2CO3 (a.q., 300 mL) was added to the mixture. The resulting solid was filtered to give the crude product, which was purified by column chromatography (DCM:MeOH=30:1) to give the product of 6-amino-5-bromo-2-cyclopropyl-N-methylbenzofuran-3-carboxamide (5.3 g, yield: 78%). 1H-NMR (400 MHz, CDCl3) δ 7.69 (s, 1H), 6.77 (s, 1H), 5.88 (s, 1H), 4.11 (s, 2H), 3.04 (d, J=4.8 Hz, 3H), 2.69˜2.73 (m, 1H), 1.10˜1.16 (m, 2H), 1.07˜1.09 (m, 2H). MS (M+H)+: 309/311.

1. stirringAfter stirring for another 2 hours
2. concentrationthe reaction mixture was concentrated in vacuum and Na2CO3 (a.q., 300 mL)
3. additionwas added to the mixture
4. filtrationThe resulting solid was filtered
5. customto give the crude product, which
6. customwas purified by column chromatography (DCM:MeOH=30:1)