N, N, N′, N′‐Tetrabromobenzene‐1, 3‐disulfonamide and Poly(N‐bromo‐N‐ethylbenzene‐1, 3‐disulfonamide) as Mild and Efficient Catalysts for Solvent‐free Synthesis of N‐Cyclohexyl‐2‐aryl(alkyl)‐imidazo[1, 2‐a]pyridin‐3‐amine Derivatives. (1st May 2014)