ChemInform Abstract: An Efficient Synthesis of Novel 3‐Hydroxy‐12‐arylbenzo[a]xanthen‐11‐ones and 5, 12‐Diarylxantheno[2, 1‐a]xanthene‐4, 12‐diones Using pTSA in [bmim]BF4. Issue 2 (14th January 2014)