8-Fluoro-5-(2-fluoro-4-iodo-phenylamino)-imidazo[1,5-a]pyridine-6-carboxylic acid (0.20 g, 0.48 mmol), O-(2-vinyloxyethyl)-hydroxylamine (55 mg, 0.53 mmol), EDCI (102 mg, 0.53 mmol), HOBt (72 mg, 0.53 mmol) and DIPEA (90 μL, 0.53 mmol) were dissolved in DMF (10 mL) and the reaction mixture stirred at room temperature for 16 hours before being concentrated in vacuo. The resultant residue was dissolved in ethyl acetate (10 mL), washed with aqueous saturated sodium bicarbonate solution (10 mL) and the aqueous fraction extracted twice with ethyl acetate (2×10 mL). The combined organic fractions were washed with brine (20 mL), dried (MgSO4) and concentrated in vacuo. The resultant residue was subjected to flash chromatography (SiO2, gradient 0-10% methanol in DCM) to yield the title compound as a pale yellow solid (200 mg, 83%). LCMS (Method B): RT=3.41 min, [M+H]+=501.
