To a solution of 1-(2-cyclopropyl-3-methylimidazo[1,2-a]pyridin-6-yl)-4-hydroxypyridin-2(1H)-one (87 mg), (5-bromo-3-thienyl)methanol (119 mg) and tributylphosphine (188 mg) in THF (4 ml) was added 1,1′-(azodicarbonyl)dipiperidine (234 mg), and the reaction mixture was stirred at 60° C. for 3 h. The reaction mixture was then cooled to room temperature, concentrated, and purified by silica gel column chromatography (hexane/EtOAc then MeOH/EtOAc). The resulting solid was recrystallized from EtOH/hexane to give the title compound (38 mg) as a white solid.
