72587-15-6

72587-18-9

The general procedure for the synthesis of 3-amino-2-chloro-5-(trifluoromethyl)pyridine from 5-(trifluoromethyl)-3-nitro-2-chloropyridine was as follows: zinc(II) dichloride dihydrate (4.39 g, 19.5 mmol) was added to 2-chloro-3-nitro-5-(trifluoromethyl)pyridine (1.00 g, 4.41 mmol) in ethyl acetate (25 mL) solution. The resulting suspension was stirred at 80°C for 2 hours. Upon completion of the reaction, the mixture was cooled to room temperature and then slowly added dropwise to an ice-cooled saturated sodium bicarbonate solution (100 mL). After the temperature was brought to room temperature, the product was separated. The suspension was filtered through a diatomaceous earth layer and the residue was washed four times with ethyl acetate (50 mL each time). The filtrate and washings were combined and washed sequentially with saturated sodium bicarbonate solution, water and saturated aqueous sodium chloride solution. The organic phase was dried over magnesium sulfate, filtered and concentrated to dryness. Yield: 0.78 g (90%). 1H-NMR (CD2Cl2, 400 MHz) data were as follows: δ=4.4 (br s, 2H), 7.24 (d, 1H), 8.02 (d, 1H).