1,1'-Carbonyldiimidazole → 2-(4-Bromophenyl)-N-(1-ethyl-3-pyrrolidinyl)-3H-imidazo[4,5-b]pyridine-3-acetamide

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Reaction Steps

A suspension of 2-(4-bromophenyl)-3H-imidazo[4,5-b]pyridine-3-acetic acid (5.0 g, 0.0151 mole), 1,1'-carbonyldiimidazole (2.45 g, 0.0151 mole), and anhydrous tetrahydrofuran (100 ml) was stirred at room temperature with a stream of nitrogen bubbling through it for 3 hours. The nitrogen flow was stopped and a solution of 1-ethyl-3-aminopyrrolidine (1.89 g, 0.0166 mole) in dry tetrahydrofuran (25 ml) was added. The solution was stirred at room temperature under nitrogen for 2 hours. The reaction mixture was concentrated in vacuo and the residue triturated in water (100 ml) and filtered. The filter cake was recrystallized from isopropyl alcohol-isopropyl ether to give 4.64 g (72%) of white needles, mp 202.5°-204° C.

Provenance & Evidence