A solution of 3-(5-chloro-2-methoxy-benzenesulfonylamino)-N-[4-(N-hydroxycarbamimidoyl)-phenyl]-benzamide (110 mg, 0.23 mmol) in tetrahydrofuran (7.0 ml) under argon was treated with pyridine (37 mg, 2 equiv.) and cooled to 0° C. A solution of thionyl chloride (28 mg, 1.01 equiv.) in dichloromethane (1.0 ml) was then added dropwise in 6 min. The mixture was stirred at 0° C. for 20 min and then at room temperature for 45 min. The solvent was evaporated and the residue diluted with water and extracted with ethyl acetate. The organic phase was dried over sodium sulfate and evaporated. Purification via preparative HPLC (Column: ZORBAX ECLIPSE XDB-C18, 21.2×50 mm, 5 um, PN 970050-902, SN USDN001082. Gradient: 0-1.2 min: 10% CH3 CN in (water+0.1% HCO2H), 1.2-4.7 min: increasing of CH3CN from 10% to 95%, 4.7-5.7 min: 95% of CH3CN, 5.7-59 min: decreasing of CH3CN from 95% to 10%. Program end at 6 min. Flow:30 ml/min) yielded the title compound as a light green solid (11 mg, 9%), MS (ISP): m/e=519.1 (M−H).
