Bromine → 2-Methyl-4-(1,2,2,2-tetrafluoro-1-trifluoromethyl-ethyl)-6-thiocyanato-phenylamine

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Reaction Steps

To a solution of 2-methyl-4-(1,2,2,2-tetrafluoro-1-trifluoromethyl-ethyl)-phenylamine (5.0 g, 18.20 mmol) (prepared according to EP 1,006,102) in acetic acid (30 ml) was added a solution of potassium thiocyanate (7.25 g, 74.62 mmol) in acetic acid (20 ml). The solution was cooled to 5° C. before the addition of bromine (3.2 g, 1.03 ml) in acetic acid (10 ml). The reaction mixture was allowed to warm to ambient temperature and was stirred at ambient temperature for 3 hours. The reaction mixture was quenched by pouring into water. The mixture was extracted with ethyl acetate (3×100 ml). The combined organic extracts were washed successively with aqueous sodium hydroxide (10 g/l) (100 ml), water (100 ml) and brine (100 ml), dried over sodium sulfate and concentrated. The residue was purified by column chromatography on silica gel (eluent: ethyl acetate/cyclohexane 1:3) to give 2-methyl-4-(1,2,2,2-tetrafluoro-1-trifluoromethyl-ethyl)-6-thiocyanato-phenylamine (3.7 g, 61.2% yield). 1H-NMR (CDCl3, 400 MHz): 7.68 (s, 1H), 7.33 (s, 1H), 5.73 (s, 2H), 2.59 (s, 6H) ppm.

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