1,3-Dibromo-5,5-dimethylhydantoin （DBH）/kaolin： An efficient reagent system for the synthesis of 14-aryl-14H- dibenzo[aj]xanthenes under solvent-free conditions

1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in relatively short reaction times in good to high yields.