To a solution of 4-chlorophenylsulfonylacetonitrile (1.10 g, 5.10 mmol) in dry acetone (12 ml) first dry potassium carbonate (1.41 g, 10.2 mmol) and then 3,5-bis(trifluoromethyl)phenyl isothiocyanate (1,44 g, 5.31 mmol) were added. The resulting mixture was stirred at room temperature under nitrogen for 1 h, and then filtered. To the filtrate a solution of sodium hydrogencarbonate (0.86 g) in water (15 ml) and methyl iodide (0.945 ml, 15.3 mmol) was added. The mixture was stirred at room temperature for 3.5 h. Then pH was adjusted to ˜4 with 1N HCl. The precipitate was filtered off and washed with water to give 2.39 g (93%) of the title compound. Recrystallisation could be done from ethyl acetate/heptane 1:3. Mp 150.5-152.5° C. 1H NMR (300 MHz, CDCl3): δ=2.25 (s, 3H), 7.57 (d, 2H), 7.79 (s, 2H), 7.83 (s, 1H), 7.88 (d, 2H), 10.0 (br s, 1H); MA calc for C18H11ClF6N2O2S2: C, 43.17%; H, 2.21%; N, 5.59%. Found: C, 43.25%; H, 2.16%; N, 5.59%.
