Ammonium Chloride → 5-Acetylfuro(2,3-c)pyridine

5-Ethoxycarbonylfuro[2,3-c]pyridine obtained in Example 2(3.82 g, 20.0 mmol) was dissolved in tetrahydrofuran (50 mL) and cooled to −30° C. To the cooled solution, 22.0 mL (22.0 mol) of 1.0 M solution of methyllithium/diethyl ether was added, and the solution was stirred for 2 hours at the same temperature, the reaction mixture was then poured into 100 mL of 5% ammonium chloride aqueous solution which had been cooled on ice, and the product was extracted twice with 100 mL of ethyl acetate. After washing with 100 mL of saturated sodium bicarbonate aqueous solution and 100 mL of saturated saline water, the extract was concentrated to give 3.12 g of crude product. This product was purified by column chromatography on silica gel, giving 2.48 g (77.0% yield) of 5-acetylfuro[2,3-c]pyridine.