反应详情

温度

70 °C

To the resulting stirred mixture from stage 1, at ambient temperature under argon, was added acetic acid (125 mL), 1H-2-benzopyran-1,4(3H)-dione (compound of formula (III)) (16.2 g, 100 mmol) and ammonium acetate (7.7 g, 100 mmol). The reaction mixture was then heated to 70° C. and distilled for 2 hours. The resulting slurry was cooled to ambient temperature and water (75 mL) added. The slurry was stirred for 30 minutes at ambient temperature then filtered. The filter cake was washed with tert-butyl methyl ether (62.5 mL) and dried to give the title compound as a yellow solid (24.8 g). The material obtained was spectroscopically identical to that obtained in Stage 2, Example 3.

1. distillationdistilled for 2 hours
2. temperatureThe resulting slurry was cooled to ambient temperature
3. additionwater (75 mL) added
4. filtrationthen filtered
5. washThe filter cake was washed with tert-butyl methyl ether (62.5 mL)
6. customdried