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Synthesis of compound 169.2. Concentrated sulfuric acid (1.9 mL) was slowly added to a solution of 2-chloropyridine-5-acetic acid (5.0 g, 29.23 mmol, 1.0 equiv) in methanol (50 mL) at room temperature. The reaction mixture was stirred at room temperature for 1 hour. Upon completion of the reaction, the mixture was poured into saturated sodium bicarbonate solution and extracted three times with ethyl acetate (EtOAc). The organic layers were combined, dried with anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to afford methyl 2-chloro-5-pyridylacetate (169.2, 5.0 g, 92.4% yield). MS (ES): m/z 185.4 [M + H]+.