Synthesis
To a stirred solution of Intermediate 1 (8.2 g, 30 mmol) and triethylamine (6.07 g, 8.36 mL, 60 mmol) in anhydrous dichloromethane (120 mL) at 0 °C was slowly added methanesulfonyl chloride (5.49 g, 3.71 mL, 48 mmol). After 2 hours of reaction at 0°C, additional triethylamine (6 mmol) and methanesulfonyl chloride (4.8 mmol) were added. After 2 hours of reaction, thin layer chromatography (TLC, unfolding agent: hexane/ethyl acetate, 1:1) showed complete reaction. The reaction mixture was diluted with dichloromethane (120 mL) and washed sequentially with saturated sodium bicarbonate solution (2 x 240 mL) and water (2 x 240 mL), and the organic phase was dried, filtered, and concentrated to afford 5-(chloromethyl)-4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazole (8.0 g, 27 mmol, 90% yield) as a yellow solid.