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Step 1: 3-(Trifluoromethyl)pyridin-2(1H)-one (25.0 g, 0.15 mol) was dissolved in acetic acid (300 mL) and sodium acetate (15.1 g, 0.18 mol) and bromine (8.6 mL, 0.17 mol) were added sequentially, dropwise. The reaction mixture was stirred at 80°C overnight. After completion of the reaction, the mixture was concentrated, diluted with saturated aqueous sodium bicarbonate and extracted twice with ethyl acetate. The organic layers were combined, washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated. Purification by column chromatography (petroleum ether/ethyl acetate = 7/2) afforded the target compound 5-bromo-3-(trifluoromethyl)pyridin-2(1H)-one (P45a) (29.7 g, 80% yield) as a white solid.

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[4] Patent: US2013/12491, 2013, A1. Location in patent: Paragraph 0171; 0172