反应详情

温度

0 °C

To 2,4-diamino-5-(7,8-dimethoxy-2H-1-benzopyran-5-ylmethyl)pyrimidine (3.90 g, 12.4 mmol) in 200 mL of boiling water was added a solution of maleic acid, prepared by dissolution of maleic anhydride (1.25 g, 12.7 mmol) in 50 mL of hot water. After cooling to 0° C., the crystalline salt was filtered, washed with cold water, and dried at 75° C. to give 5.07 g (94.9%) of the title compound. Anal. Calcd for C20H22N4O7 : C, 55.81; H, 5.15; N, 13.02. Found: C, 55.78; H, 5.18; N, 12.98.

1. filtrationthe crystalline salt was filtered
2. washwashed with cold water
3. customdried at 75° C.