A series of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one derivatives were synthesized via the three-component coupling from aromatic aldehydes, 2-naphthol and 5,5–dimethylcyclohexane -1,3-dione catalyzed by NaHSO4 in ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4). The reaction proceeded with good yields under short reaction time. The NaHSO4 was not expensive and the ionic liquid could be reused. The proposed method is efficient and environmentally friendly.