“…the anti-ulcer drug omeprazole gave rise to lasting interest in this class of compounds. [1][2][3][4][5] Our continuing research on synthesis and reactions of benzimidazole derivatives led to investigations in arylsulfonation of 5 -(chloro, nitro, methyl)-2-alkylbenzimidazoles. To further investigate the nature of chemical bonds and of intermolecular interactions in these derivatives [6] we had carried out single-crystal X-ray structure d e t e r m i n a t i o n s in the past.…”