An Efficient and Green One-pot Synthesis of 12-Aryl-8,9,10,12-tetra hyd robenzo[a]xanthen-11 -one Deriva- tives Promoted by Sulfamic Acid in [BMIM]BF4 Ionic Liquid

An efficient and green procedure for the synthesis of novel 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen- 11- one derivatives has been described through one-pot condensation of 2-naphthol, arylaldehyde and 5,5-dimethyl- cyclohexane-l,3-dione in the presence of sulfamic acid （NH2SO3H） in ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate （[BMIM]BF4）. These reactions proceed with good yields under short reaction time. Furthermore, the green catalytic system can be recycled specific times with no decreases in yields and reaction rates.