1,1'-Carbonyldiimidazole → (2-(3-azidopropyl)-5-(2,5-difluorophenyl)-2-phenyl-1,3,4-thiadiazol-3(2H)-yl)(1H-imidazol-1-yl)methanone

To a solution of 2-(3-azidopropyl)-5-(2,5-difluorophenyl)-2-phenyl-2,3-dihydro-1,3,4-thiadiazole (0.492 g, 1.37 mmol) in THF (8 mL) was added 1,1′-carbonyl diimidazole (0.266 g, 1.64 mmol). After stirring at 75° C. for 2 hours, the reaction mixture was concentrated under reduced pressure and dissolved in dichloromethane (20 mL). The solution was washed with HCl (0.5 M), dried over Na2SO4 and concentrated to provide the crude product.