Tetrahydrofuran → 2-(3-Chlorophenyl)-3-[2-(4-methyl-1-piperazinyl)-2-oxoethyl]3H-imidazo[4,5-b]pyridine fumarate

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Reaction Steps

A stream of nitrogen gas was bubbled through a stirred solution of 2-(3-chlorophenyl)-3H-imidazo[4,5-b]pyridine-3-acetic acid (3.68 g, 0.0128 mole), 1,1'-carbonyldiimidazole (2.07 g, 0.0128 mole), and anhydrous tetrahydrofuram (70 ml) for 21/2 hrs. at room temperature. A solution of N-methylpiperazine in 10 ml of tetrahydrofuran was added (rapid drop) and stirring was continued for 4 hrs. at room temperature. The tetrahydrofuran was evaporated and the residue was dissolved in methylene chloride (75 ml). The methylene chloride solution was washed with water (2×30 ml), dried over sodium sulfate, and concentrated in vacuo. The residue was converted to the sesquifumarate salt and crystallized from isopropyl alcohol-isopropyl ether. Recrystallization twice from isopropyl alcohol-isopropyl ether gave 3.2 g (46%) of a white solid, mp 190°-193° C. with decomposition.

Provenance & Evidence