Oxalyl chloride (0.285 mL) was added to a solution of 1,2-phenylenediacetic acid (100 mg, 0.515 mmol) in dichloromethane, followed by 5 drops of DMF. The mixture was stirred at room temperature for 1.5 hours and cooled to 0° C. To the cooled mixture was added DMAP (63 mg, 0.62 mmol) and 3-aminophenyl trifluoromethyl sulfone (116 mg, 0.515 mmol). The mixture was allowed to warm to room temperature and extracted with ethyl acetate. The organic layer was washed with water, brine, dried and purified to give the title compound. 1H NMR (300 MHz, DMSO-d6) δ 11.31 (br s, 1H), 8.51 (s, 1H), 8.04 (m, 1H), 7.75 (d, J=5.1 Hz, 2H), 7.28 (m, 1H), 7.19 (m, 3H), 3.75 (s, 2H, CH2), 3.62 (s, 2H, CH2). MS 401.9 [M++1].
