反应详情

Compound 45 (0.300 g, 1.50 mmol) was diluted in anhydrous benzene (10 mL). N-Bromosuccinimide (0.280 g, 1.57 mmol) and a catalytic amount (˜0.020 g) of benzoyl peroxide were added, and the mixture was heated to reflux under nitrogen until an orange tint was no longer visible in the solution refluxing in the condenser (around 2 h 40 min). The mixture was cooled, concentrated, and purified by flash column chromatography (SiO2), eluting with a gradient of 10% to 12% EtOAc in CH2Cl2 to yield the product (0.262 g, 63%) as a flocculent yellow solid. The 1H NMR chemical shifts for this compound are identical to those previously reported in the literature. 1H-NMR (500 MHz; CDCl3): δ 8.44 (br d, J=8.6 Hz, 1 H), 8.30 (br s, 1 H), 8.17 (d, J=9.0 Hz, 1 H), 7.82 (m, J=9.1 Hz, 2 H), 7.72 (dd, J=8.6, 2.1 Hz, 1 H), 4.67 (s, 2 H), 2.29 (s, 3 H).

1. temperaturethe mixture was heated
2. temperatureto reflux under nitrogen until an orange tint
3. temperaturerefluxing in the condenser (around 2 h 40 min)
4. temperatureThe mixture was cooled
5. concentrationconcentrated
6. custompurified by flash column chromatography (SiO2)
7. washeluting with a gradient of 10% to 12% EtOAc in CH2Cl2