Dipropylamine → 2-(3,4-Dichlorophenyl)-N,N-dipropyl-3H-imidazo[4,5-b]pyridine-3-acetamide hydrate

Participants

Reaction Steps

Under nitrogen bubbling, a mixture of 2-(3,4-dichlorophenyl)-3H-imidazo [4,5-b]pyridine-3-acetic acid (3.5 g, 0.011 mole) and 1,1'-carbonyldiimidazole (1.95 g, 0.011 mole) in 120 ml of tetrahydrofuran was stirred at room temperature for 31/2 hrs. Then, under nitrogen atmosphere, dipropylamine (2.43 g, 0.024 mole) was added at room temperature and the reaction mixture was heated at reflux for 6 hrs. The reaction mixture was filtered, and the filtrate was evaporated to dryness. The residue was treated with water and refrigerated. The solid was collected by filtration, washed with water, and dried under high vacuum at 50°-60° C. overnight. The solid was recrystallized from isopropyl alcohol-water, collected, washed with water, and dried under high vacuum at 50°-60° C. overnight. Two crops gave 1.9 g (43%) of crystals, mp 122°-123° C.

Provenance & Evidence