The general procedure for the synthesis of 3-chloro-2-pyridinemethanol from 3-chloro-2-pyridinecarboxylic acid is as follows: to a solution of tetrahydrofuran (THF, 40 mL) containing 3-chloro-2-pyridinecarboxylic acid (2.1 g, 13.33 mmol, 1.00 eq.) was added sequentially triethylamine (Et3N, 2.7 g, 26.68 mmol, 2.00 eq.) and chloroformic acid isopropyl chloroformate (2.45 g, 19.99 mmol, 1.50 eq.) were stirred and added dropwise at 0 °C. The reaction mixture was continued to be stirred at room temperature for 1 hour. After completion of the reaction, the solid impurities were removed by filtration. Sodium borohydride (NaBH4, 1.53 g, 40.44 mmol, 3.00 equiv) was added to the filtrate and the resulting solution was stirred at room temperature for 2 hours. The reaction mixture was diluted with 50 mL of water and extracted with ethyl acetate (EtOAc, 2 x 100 mL). The organic layers were combined, washed with 50 mL of saturated sodium chloride (NaCl) solution, dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography with the eluent of ethyl acetate/petroleum ether (1:6) to give 0.9 g (47% yield) of 3-chloropyridine-2-methanol as a colorless oil.
