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Step 1: Synthesis of 5-bromo-4-(trifluoromethyl)pyridin-2-amine To a stirred solution of 4-(trifluoromethyl)pyridin-2-amine (2.5 g, 15.42 mmol) in dichloromethane (250 mL) was added N-bromosuccinimide (2.74 g, 15.42 mmol) in batches. The reaction was carried out at room temperature and under light protection with continuous stirring for 6 hours. After completion of the reaction, the reaction mixture was diluted with 1N NaOH solution (20 mL) and extracted with dichloromethane (2 x 100 mL). The organic layers were combined, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the title compound (3.2 g, 86% yield). 1H NMR (400 MHz, CDCl3): δ 8.28 (s, 1H), 6.77 (s, 1H), 4.73 (brs, 2H). ESI-MS: Calculated: 239.95; Measured: 239.10 [M-H]?

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