To a solution of methyl 2-fluoro-5-[(hexylamino)methyl]benzoate in DCM (13 mL) were added 4-bromobenzenesulfonyl chloride (200 mg; 0.79 mmol) and TEA (0.13 mL; 0.94 mmol). The reaction mixture was stirred at room temperature for 2 hours under N2 atmosphere. The mixture was poured into a saturated solution of NaHCO3 and extracted with DCM (2×100 mL). The combined organic layers were then washed with a saturated solution of NH4Cl (150 mL) and with brine (150 mL), dried over magnesium sulfate, filtrated and the solvent was removed under reduced pressure. Purification by flash chromatography on silica gel (c-Hex/EtOAc, 95:5) gave 96 mg (25%) of the title compound as a colorless oil. HPLC, Rt: 5.13 min (purity=99.1%). LC/MS: M+(ESI): 486.23; 1H NMR (CDCl3) δ: 7.78 (m, 1H), 7.72 (m, 4H), 7.55 (m, 1H), 7.12 (m, 1H), 4.31 (s, 2H), 3.93 (s, 3H), 3.09 (t, J=7.5 Hz, 2H), 1.85 to 1.05 (m, 8H), 0.81 (t, J=6.9 Hz, 3H).
