反应详情

To 4-fluoro-1H-pyrazole, 28-d, (2 g, 23 mmol) and cyanamide (0.97 g, 23 mmol) in dioxane (5 mL) was added 4N HCl in dioxane (15 mL). The mixture was gently refluxed with stirring for 2 h under nitrogen. During the course of the reaction the product crystallizes. After cooling to room temperature, 10 mL of anhydrous ether was added and the mixture was allowed to stand for 30 min. The white solid was collected by filtration, washed with anhydrous ether and dried to constant weight in vacuuo providing the product, 28-e, (3 g, 80%).

1. temperatureThe mixture was gently refluxed
2. customDuring the course of the reaction the product
3. customcrystallizes
4. addition10 mL of anhydrous ether was added
5. waitto stand for 30 min
6. filtrationThe white solid was collected by filtration
7. washwashed with anhydrous ether
8. customdried to constant weight in vacuuo