1,1'-Carbonyldiimidazole → 3-[({[8-(Cyclohexylmethoxy)-2-methylimidazo[1,2-a]pyridin-3-yl]carbonyl}amino)sulfonyl]propyl acetate

Participants

Reaction Conditions

Reaction Steps

To a suspension of 300 mg of 8-(cyclohexylmethoxy)-2-methylimidazo[1,2-a]pyridine-3-carboxylic acid in 5 ml of THF was added 253 mg of 1,1′-carbonyldiimidazole, followed by stirring at 60° C. for 1 hour. Subsequently, 283 mg of 3-(aminosulfonyl)propyl acetate and 389 μl of 1,8-diazabicyclo[5.4.0]-7-undecene were added thereto under ice-cooling, followed by stirring at room temperature overnight. To the reaction mixture were added water and ethyl acetate to carry out a layer separation operation. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the obtained residue was purified by silica gel column chromatography. Since the reaction was not completed, to the obtained purified product were added again 57 mg of 3-(aminosulfonyl)propyl acetate, 60 mg of N-[3-(dimethylamino)propyl]-N′-ethylcarbodiimide hydrochloride, 38 mg of 4-(dimethylamino)pyridine, and 2 ml of DMF, followed by stirring at room temperature overnight. To the reaction mixture were added a saturated aqueous ammonium chloride solution and chloroform to carry out a layer separation operation. The organic layer was dried over anhydrous sodium sulfate, the solvent was evaporated under reduced pressure, and the obtained residue was purified by silica gel column chromatography. To the obtained product were added ethyl acetate and ethanol, followed by stirring. The resulting solid was collected by filtration and dried to obtain 149 mg of 3-[({[8-(cyclohexylmethoxy)-2-methylimidazo[1,2-a]pyridin-3-yl]carbonyl}amino)sulfonyl]propyl acetate.

Provenance & Evidence