To a solution of 7-(2-fluoro-4-iodo-phenylamino)-benzo[d]isothiazole-6-carboxylic acid (328 mg, 0.79 mmol) and diisopropylethylamine (0.41 mL, 2.37 mmol) in DMF (2 mL) were added O-(2-vinyloxy-ethyl)-hydroxylamine (163 mg, 1.58 mmol), EDCI (303 mg, 1.58 mmol) and HOBt (213 mg, 1.58 mmol). The reaction mixture was stirred for 18 hours at room temperature, diluted with ethyl acetate, and washed with water then a saturated aqueous solution of sodium hydrogen carbonate, then brine, before being dried (Na2SO4), filtered and concentrated in vacuo. The resultant residue was subjected to flash chromatography (Si—PPC, gradient 0% to 100%, TBME in cyclohexane) to afford the title compound as a yellow foam (194 mg, 49%). LCMS (method B): RT=3.99 min, [M+H]+=500.
