The application of poly(N, N'-dibromo-N-ethyl-benzene-1,3-disulfonamide) and N, N, N', N'-tetrabromobenzene-1,3-disulfonamide as catalysts for one-pot synthesis of 2-aryl-1-arylmethyl-1H-1,3-benzimidazoles and 1,5-benzodiazepines, and new reagents for synthesis of benzimidazoles.

Poly(N, N'-dibromo-N-ethyl-benzene-1, 3-di-sulfonamide) (PBBS) and N, N, N', N'- tetrabromobenzene-1,3-disulfonamide (TBBDA) are effective catalysts for the one-pot synthesis of 2-aryl-1-arylmethyl-1H-1,3-benzimidazoles and 1,5-benzodiazepines and new reagents for synthesis of benzimidazoles from o-phenylenediamine (OPDA) with aldehydes and ketones at room temperature with good to high yield.