To a solution of 7-acetyl-2-oxo-2,3-dihydro-1,3-benzothiazol-4-yl benzyl carbonate (280 mg) in dry THF (20 ml) stirring under nitrogen, was added phenyltrimethylammonium tribromide (330 mg). The mixture was heated at 80° C. for 2 h and then diluted with water, extracted with ethyl acetate, dried (MgSO4), filtered, and evaporated in vacuo. The residue was purified on a 40 g silica biotage cartridge and eluted with 20% ethyl acetate-cyclohexane to give the title compound (186 mg). LCMS RT=3.43 min.
