反应详情

A suspension of 2-(4-chlorophenyl)-3H-imidazo[4,5-b]pyridine-3-acetic acid (5.0 g, 0.0174 mole), 1,1'carbonyldiimidazole (2.82 g, 0.0174 mole) and dry tetrahydrofuran (100 ml) was stirred at room temperature for two hours with nitrogen bubbling through it. A solution of 4-amino-1,2-diethyl-pyrazolidine (7.5 g, 0.0522 mole) in tetrahydrofuran (6 ml) was added and the reaction mixture was stirred at room temperature overnight under nitrogen. The reaction mixture was evaporated under reduced pressure to an oil. Water (200 ml) was added, and the resulting suspension was stirred. The solid was collected by filtration, rinsed twice with water, twice with 5% potassium hydroxide solution and twice again with water. The solid was dissolved in hot isopropyl alcohol, filtered hot, and acidified with hydrogen chloride in isopropyl alcohol. Isopropyl ether was added to the cloud point, and upon cooling to room temperature, a solid precipitated. The solid was collected by filtration, rinsed with isopropyl ether, and dried under high vacuum to give 4.8 g (56%) of title compound, mp 220° C. (darkens), 228°-230° C. (melts).

1. stirringthe reaction mixture was stirred at room temperature overnight under nitrogen
2. customThe reaction mixture was evaporated under reduced pressure to an oil
3. additionWater (200 ml) was added
4. stirringthe resulting suspension was stirred
5. filtrationThe solid was collected by filtration
6. washrinsed twice with water, twice with 5% potassium hydroxide solution and twice again with water
7. dissolutionThe solid was dissolved in hot isopropyl alcohol
8. filtrationfiltered hot
9. additionIsopropyl ether was added to the cloud point
10. temperatureupon cooling to room temperature
11. customa solid precipitated
12. filtrationThe solid was collected by filtration
13. washrinsed with isopropyl ether
14. customdried under high vacuum