To a solution of 7-(2-fluoro-4-iodo-phenylamino)-benzo[d]isothiazole-6-carboxylic acid (377 mg, 0.91 mmol) and diisopropylethylamine (0.47 mL, 2.73 mmol) in DMF (4 mL) were added O—((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-hydroxylamine (268 mg, 1.82 mmol), EDCI (349 mg, 1.82 mmol) and HOBt (246 mg, 1.82 mmol). The reaction mixture was stirred for 18 hours at room temperature, diluted with ethyl acetate, and washed with water, 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 solid (266 mg, 54%). LCMS (method B): RT=4.04 min, [M+H]+=544.
