反应详情

To 2,4-diamino-5-(7,8-dimethoxy-2H-1-benzopyran-5-ylmethyl)pyrimidine (5.00 g, 15.9 mmol) in 450 mL of boiling methanol was added a solution of citric acid monohydrate (3.34 g, 15.9 mmol) in 50 mL of methanol. The solution was treated with charcoal, filtered, and evaporated to dryness. Further drying at 40° C. in a vacuum oven gave 8.01 g (99.5%) of the title compound. Karl Fisher analysis: 5.3% H2O. Anal. Calcd for C16H18N4O3.C6H8O7.1.5H2O: C, 49.53; H, 5.48; N, 10.50. Found: C, 49.54; H, 5.49; N, 10.47.

1. filtrationfiltered
2. customevaporated to dryness
3. customFurther drying at 40° C. in a vacuum oven