The general procedure for the synthesis of 2-chloro-6-methoxy-4-(trifluoromethyl)pyridine from methanol and 2,6-dichloro-4-trifluoromethylpyridine was as follows: to a solution of anhydrous methanol (40 ml) of 2,6-dichloro-4-(trifluoromethyl)pyridine (2.0 g), anhydrous methanol (7 ml) solution of sodium hydroxide (1.85 g) was slowly added, and the reaction mixture was stirred at room temperature. Subsequently, the reaction system was warmed up to 50°C under nitrogen protection and maintained at this temperature for 2 hours. After completion of the reaction, the mixture was cooled to room temperature. The reaction mixture was extracted with pentane (2 x 100 ml) and concentrated under reduced pressure after combining the organic phases to afford 2-chloro-6-methoxy-4-(trifluoromethyl)pyridine (1.69 g) as a colorless oil. It was analyzed by LCMS: retention time (Rt) was 1.75 min, and the mass-to-charge ratio (m/z) was 212/214 [M + H]+. 1H-NMR (400 MHz, CDCl3) data were as follows: δ 4.00 (s, 3H), 6.89 (s, 1H), 7.12 (s, 1H).
