1,1'-Carbonyldiimidazole → HCID 23037392, compound

Participants

Reaction Steps

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 though it. A solution of 4-amino-1,2-diethyl-pyrazoline (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).

Provenance & Evidence