Concentrated sulfuric acid (1 g) was added slowly and dropwise to a solution of 2-(pyridin-4-yl)acetic acid (4 g, 29.2 mmol) in methanol (40 mL). The reaction mixture was heated to reflux and maintained for about 2 hours. Upon completion of the reaction, methanol was removed by rotary evaporator under reduced pressure. Water was added to the residue and extracted with ethyl acetate. The organic phases were combined, washed with saturated brine and dried over anhydrous sodium sulfate. After filtration, the organic phase was concentrated under reduced pressure to give the crude product. Finally, the crude product was purified by column chromatography (petroleum ether: ethyl acetate = 10:1) to afford methyl pyridine-4-acetate (3.5 g, yield: 79.55%).
