反应详情

A mixture of the title compound from Step C (0.38 g, 1.15 mmol), NBS (0.24 g, 1.38 mmol) and catalytic amount of AIBN in carbon tetrachloride (5 ml) was heated to reflux for 3 days. During the period more AIBN was added daily. The mixture was cooled and concentrated. The title compound was obtained after flash column using hexane as the eluant. 1H NMR (CDCl3, 500 MHz): δ 7.91 (s, 1H), 7.80 (s, 1H), 4.75 (s, 2H).

1. temperaturewas heated
2. temperatureto reflux for 3 days
3. temperatureThe mixture was cooled
4. concentrationconcentrated