{6-[4-(4-Trifluoromethoxy-phenyl)-piperazine-1-sulfonyl]-indol-1-yl}-acetic acid methyl ester was prepared from 1-(4-trifluoromethoxy-phenyl)-piperazine following the procedures outlined in Example 34. A mixture of {6-[4-(4-trifluoromethoxy-phenyl)-piperazine-1-sulfonyl]-indol-1-yl}-acetic acid methyl ester (45 mg, 0.09 mmol), 1M LiOH (2 mL), tetrahydrofuran (6 mL), and methanol (2 mL) was stirred at rt for 3 h. The reaction was poured into 1M HCl (50 mL) and extracted with ethyl acetate (40 mL×2). The combined organic extracts were dried, filtered, and concentrated to give {6-[4-(4-trifluoromethoxyphenyl)-piperazine-1-sulfonyl]-indol-1-yl}-acetic acid: 1H NMR (400 MHz, DMSO-d6): 67.89 (s, 1H), 7.77 (d, 1H), 7.63 (d, 1H), 7.38 (d, 1H), 7.14 (d, 2H), 6.93 (d, 2H), 6.61 (d, 1H), 5.19 (s, 2H), 3.23-3.15 (m, 4H), 3.03-2.95 (m, 4H); MS (ESI): 483.7 (M+H).
