Tetrahydrofuran → Isopropyl alcohol isopropyl ether

Participants

Reaction Steps

A suspension of 4.4 g (0.0133 mole) of 2-(4-bromophenyl)-3H-imidazo[4,5-b]pyridine-3-acetic acid, 2.2 g (0.0133 mole) of 1,1'-carbonyldiimidazole, and anhydrous tetrahydrofuran (100 ml) was stirred at room temperature with a stream of nitrogen bubbling through the mixture for 3 hours. To the resulting solution was added dropwise a solution of 1.3 g (0.0133 mole) of N-methyl-piperazine in 10 ml of tetrahydrofuran. The reaction mixture was stirred at room temperature for 18 hours. The tetrahydrofuran was evaported and the residue taken up in methylene chloride (75 ml) and washed with water (3×25 ml). The methylene chloride solution was dried over sodium sulfate and concentrated in vacuo. The residue was converted to the fumarate salt and crystallized from ethanol-ethyl acetate, giving 6.5 g. Recrystallization from ethanol-ethyl acetate and then from isopropyl alcohol-isopropyl ether gave 3.2 g (45%) of white solid, mp 203°-203.5° C. with decomposition.

Provenance & Evidence