A simple, facile, and efficient procedure for the synthesis of 2-arylthizolines and 2- arylimidazolines has been developed by the simple condensation of nitriles with 2- aminoethanethiol or ethylenediamine catalyzed by 1, 3-dibromo-5, 5-dimethylhydantoin under solvent-free conditions. Selective preparation of bisthiozolines and monoimidazolines from dinitriles and also selective conversion of arylnitriles to their corresponding 2- ...