A suspension of 8-(4-cyclobutyl-2-fluoro-phenylamino)-imidazo[1,5-a]pyridine-7-carboxylic acid (154 mg, 0.46 mmol), EDCI (105 mg, 0.55 mmol), HOBt (74 mg, 0.55 mmol), DIPEA (0.19 mL, 1.14 mmol) and O-(2-vinyloxy-ethyl)-hydroxylamine (52 mg, 0.50 mmol) in THF (2.5 mL) was stirred at room temperature for 18 hours. The reaction mixture was partitioned between DCM (20 mL) and saturated aqueous NaHCO3. The organic layer was isolated then washed with water (20 mL), followed by brine (20 mL), dried (MgSO4), filtered and concentrated in vacuo. The resultant gum was subjected to flash chromatography (Si-PPC, gradient 0% to 100%, ethyl actetate in cyclohexane) to afford the title compound as a brown gum (149 mg, 80%). LCMS (method B): RT=3.49 min, [M+H]+=411.
