a convenient and efficient procedure for the synthesis of 14-aryl or alkyl-14h-dibenzo[a,j]xanthenes by condensation of 2-naphthol and aldehydes in the presence of methylimidazolium hydrogensulfate, as a brönsted acidic ionic liquid ([hmim]hso4), is described. both aromatic and aliphatic aldehydes reactedeasily to afford the corresponding 14-aryl or alkyl-14h-dibenzo[a,j]xanthenes in good yield...