Benzenesulfonamide → 6-Benzenesulfonylcarbamoyl-1-(2-chlorobenzyl)-2-methylbenzimidazole

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Reaction Steps

N,N′-carbonyldiimidazole (0.973 g) was added to a solution of 0.902 g of 6-carboxy-1-(2-chlorobenzyl)-2-methylbenzimidazole in 20 ml of N,N-dimethylformamide, and the mixture was stirred at room temperature for 1 hour. Subsequently, a solution of 0.943 g of benzenesulfonamide and 0.913 g of diazabicycloundecene in 5 ml of N,N-dimethylformamide was added thereto, and the mixture was stirred at 100° C. for 70 hours. The reaction solution was cooled, and the solvent was distilled off under reduced pressure. Water and chloroform were added to the residue, and 10% hydrochloric acid was added thereto while being stirred until the aqueous layer was acidified. The mixed solution was extracted twice with chloroform. The resulting organic layer was washed with a saturated aqueous solution of sodium hydrogencarbonate, and the solvent was distilled off under reduced pressure. The residue was dissolved in a small amount of chloroform, and ethyl acetate was added to the solution for crystallization. The crystals were separated through filtration, and were dried to give 0.667 g of 6-benzenesulfonylcarbamoyl-1-(2-chlorobenzyl)-2-methylbenzimidazole (163).

Provenance & Evidence