Preparation of a new DABCO-based ionic liquid [H2-DABCO][H2PO4]2} and its application in the synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-d]pyrimidinone derivatives

A new acidic ionic liquid, 1,4-diazabicyclo[2.2.2]octane-1,4-diium dihydrogen phosphate {[H2-DABCO][H2PO4]2}, was prepared in a quick and straightforward process and characterized by using different methods such as FT-IR, NMR and Mass analysis. Then it was used as a reusable and new catalyst to promote the synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-d]pyrimidinone derivatives as important biologically active compounds that they are used in pharmaceutical industry. This adequate procedure possess some advantages like producing target compounds in high yields, short reaction times, simple work-up procedure and use of chief and easily preparable catalyst.