To a solution of N-(3,5-dichlorobenzyl)-N-(4-fluorobenzyl)-3-((4-fluorobenzylamino)methyl)benzenesulfonamide (75 mg, 0.13 mmol) in THF (4 mL) at rt was added 3,5-dichloro-2-hydroxybenzene-1-sulfonyl chloride (38 mg, 0.15 mmol) and Et3N (0.06 mL, 0.40 mmol) and it was stirred at rt for 1.5 h. Additional sulfonyl chloride (15 mg) and Et3N (0.05 mL) were added to the reaction mixture, and it was continued to stir for 2 h. The mixture was concentrated and the residue was purified by preparative HPLC (Condition: solvent A: 10% MeOH-90% H2O-0.1% TFA; Solvent B: 90% MeOH-10% H2O-0.1% TFA. Column 3: YMC S5 ODS 20×100 mm; 45% B to final 100% B, gradient time: 10 minutes, flow rate: 20 ml/min) to give the desired product as a white solid (56 mg, 53%). 1H NMR (CD3OD): δ 7.72 (d, J=7.2 Hz, 1H), 7.70 (d, J=2.8 Hz, 1H), 7.64 (s, 1H), 7.58 (d, J=2.8 Hz, 1H), 7.50-7.46 (m, 2H), 7.20-7.10 (m, 5H), 6.93-6.90 (m, 6H), 4.61 (s, 2H), 4.46 (s, 2H), 4.26 (s, 2H), 4.21 (s, 21-1); MS (ESI): [M−H]−=784.9.
