1214336-90-9

General procedure for the synthesis of 2-bromo-3-nitro-5-(trifluoromethyl)pyridine from 2-hydroxy-3-nitro-5-(trifluoromethyl)pyridine: 3-nitro-5-(trifluoromethyl)pyridin-2-ol (3.12 g, 15 mmol) was dissolved in acetonitrile (25 ml) and slowly added to a solution of phosphorus tribromide (8.6 g, 30 mmol). The reaction mixture was stirred at room temperature for 12 hours and then heated to reflux for 4 hours. Upon completion of the reaction, the reaction solution was slowly poured into a rapidly stirred aqueous solution of sodium bicarbonate (11 g dissolved in 60 ml of water). The aqueous phase was extracted with dichloromethane (3 x 20 ml) and the organic phases were combined and washed sequentially with water (20 ml) and saturated sodium chloride solution (10 ml). The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give the target product 2-bromo-3-nitro-5-(trifluoromethyl)pyridine (2.44 g, 9.0 mmol).

[1] Patent: US2011/230483, 2011, A1. Location in patent: Page/Page column 32
[2] Patent: WO2013/38386, 2013, A1. Location in patent: Page/Page column 80; 81
[3] Patent: WO2013/38373, 2013, A1. Location in patent: Page/Page column 52
[4] Patent: WO2013/38378, 2013, A1. Location in patent: Page/Page column 48
[5] Patent: WO2013/38381, 2013, A1. Location in patent: Page/Page column 50