Br?nsted acidic ionic liquids catalyzed the preparation of 13-aryl-5H-dibenzo[b,i]xanthene-5,7,12,14(13H)-tetraones and 3,4-dihydro-1H-benzo[b]xanthene-1,6,11(2H,12H)-triones

Article abstract of DOI:10.1007/s11164-013-1043-1

An environmentally green method for the synthesis of 13-aryl-5H-dibenzo[b, i]xanthene-5,7,12,14(13H)-tetraone and 3,4-dihydro-1H-benzo[b]xanthene-1,6, 11(2H,12H)-trione derivatives using Br?nsted acidic ionic liquids, 3-methyl-1-sulfonic acid imidazolium chloride, 1-H-3-methyl-imidazolium hydrogensulfate, triethylamine-bonded sulfonic acid, and triethylammonium hydrogensulfate as reusable catalysts under thermal solvent-free conditions is described.