反应详情

To a stirred solution of phosgene (68 mmol) in 35 mL toluene was added the title compound of Step D (4.2 g, 15.4 mmol) in 80 mL toluene at 0° C. and the reaction was stirred at room temperature overnight. The temperature was then raised to 70° C. for 4 h. After cooling to room temperature, the reaction mixture was filtrated and the solvent was removed under reduced pressure. Drying of the white precipitate under reduced pressure yielded the title compound of Step E (4.4 g, 95%) melting at 101.5-102.5° C. 1H NMR (CDCl3) δ 7.5 (d, 1H), 7.3 (d, 1H), 7.0-6.9 (br s, 1H), 4.64.5 (s, 2H).

1. temperatureThe temperature was then raised to 70° C. for 4 h
2. temperatureAfter cooling to room temperature
3. filtrationthe reaction mixture was filtrated
4. customthe solvent was removed under reduced pressure
5. customDrying of the white precipitate under reduced pressure