To a solution of 1,4-butanediol (0.315 mL, 3.6 mmol) in DMF (2.5 mL) at ambient temperature was added sodium hydride (60%, 34 mg, 0.85 mmol) and the mixture was stirred for 15 minutes. A solution of 5-bromo-4-chloro-2-fluoro-N-methyl-N-pyridin-2-yl-benzenesulfonamide (0.268 g, 0.71 mmol) in DMF (2.5 mL) was added and the mixture heated at 50° C. for 2 h. The solvent was removed in vacuo and water and DCM were added. The mixture was extracted with DCM. The organic layer was washed with brine and was dried over anhydrous MgSO4. Concentration of the filtrate provided a residue that was purified by silica gel chromatography [eluent: 50% ethyl acetate in hexane] to afford 5-bromo-4-chloro-2-(4-hydroxy-butoxy)-N-methyl-N-pyridin-2-yl-benzenesulfonamide as a solid (0.309 g). MS: 451.0 (M+H)+; tR=2.59 min (method 1).
