To a solution of 5-[4-((1S*,2R*)-2-aminocyclohexylmethyl)-2-benzyloxy-phenyl]-1,1-dioxo-2-(2-trimethylsilanylethyl)-1,2,5-thiadiazolidin-3-one (153 mg, 0.238 mmol) and diisopropylethylamine (92 mg, 0.712 mmol) in methylene chloride (5 mL) is added methanesulfonyl chloride (30 mg, 0.258 mmol) and the mixture is stirred at RT for 14 h. The mixture is poured into 1N HCl and extracted with EtOAc and the organic phase is washed with saturated NaHCO3. The organic phase is dried over magnesium sulfate and the solvent removed under reduced pressure to give the title compound.
