2-Bromoacetamide (0.12 g) and potassium carbonate (0.28 g) were added to solution of tert-butyl 6-(benzenesulfonylmethyl)-3-bromo-2-hydroxybenzoate (Intermediate 38, 0.34 g) in acetone (10 mL) and the mixture was stirred for 18 hours. The mixture was evaporated to dryness and the residue was suspended in DCM and the insoluble material was removed by filtration. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and pentane with a gradient of 50-60% to give tert-butyl 6-(benzenesulfonylmethyl)-3-bromo-2-carbamoylmethoxybenzoate (0.30 g).
