Potassium Carbonate → methyl 3-(4-acetoxy-2-chlorobenzyl)-2,7-dimethyl-3H-imidazo[4,5-b]pyridine-5-carboxylate

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Reaction Steps

A mixture of methyl 2,7-dimethyl-3H-imidazo[4,5-b]pyridine-5-carboxylate (2.70 g), 4-acetoxy-2-chlorobenzylbromide (4.85 g), potassium carbonate (2.73 g) and N,N-dimethylformamide (27 ml) was stirred at room temperature for 5 hr and left standing overnight. The reaction mixture was partitioned between ethyl acetate and saturated brine, and the resulting precipitate was collected by filtration and washed with water and ethyl acetate to give methyl 3-(4-acetoxy-2-chlorobenzyl)-2,7-dimethyl-3H-imidazo[4,5-b]pyridine-5-carboxylate (6.0 g) as a pale-brown powder. The mother liquor and washing were combined and the organic layer was separated, dried over magnesium sulfate and concentrated to dryness under reduced pressure. The residue was powdered from diethyl ether to give the second lot (680 mg) as a pale-brown powder.

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