To a suspension of 1-(α,α,α-trifluoro-m-tolyl)piperazine hydrochloride (0.43 g, 1.62 mmol) in dioxane (5 mL) a solution of NaHCO3 (0.27 g, 3.24 mmol) in water (4 mL) and a solution of 3-(4-chlorosulfonyl-phenyl)-acrylic acid (A) (0.40 g, 1.62 mmol) were added and the resultant mixture was stirred at ambient temperature for 20 hours. The reaction mixture was poured into water (50 mL) and the pH of the medium was brought to ˜4 with 2 N HCl. The precipitated solid was filtered, washed with water, and dried in vacuum to give the title compound (0.59 g, 82%). 1H NMR (DMSO-dc, HMDSO), δ: 2.96-3.67 (SH, m, overlapped with a signal of water); 6.74 (1H, d, J=16.3 Hz); 7.01-7.57 (4H, m); 7.67 (1H, d, J=16.3 Hz); 7.82 (2H, d, J=8.4 Hz); 8.00 (2H, d, J=8.4 Hz); 12.71 (1H, br s).
