反应详情

温度

0 °C

To a solution of compound ethyl 5-bromo-2-cyclopropylbenzofuran-3-carboxylate (10 g, 34 mmol) in CHCl3 (60 mL), fuming HNO3 (12 mL, 95%) was added dropwise at −20° C. over 90 min and the mixture was stirred at 0° C. for 1 hour. The reaction mixture was added to ice water and extracted with CH2Cl2. The organic layer was washed with NaHCO3 (aq.) and brine. The solvent was removed by distillation to provide the crude product of ethyl 5-bromo-2-cyclopropyl-6-nitrobenzofuran-3-carboxylate (4.5 g, yield: 40%). 1H-NMR (400 MHz, CDCl3) δ 8.26 (s, 1H), 7.95 (s, 1H), 4.46 (q, J=7.2 Hz, 2H), 3.06˜3.10 (m, 1H), 1.46 (t, J=7.2 Hz, 3H), 1.34˜1.36 (m, 2H), 1.28˜1.32 (m, 2H). MS (M+H)+: 354/356.

1. extractionextracted with CH2Cl2
2. washThe organic layer was washed with NaHCO3 (aq.) and brine
3. customThe solvent was removed by distillation