Microwave-assisted green synthesis of dibenzo[a,j]xanthenes using p-dodecylbenzenesulfonic acid as an efficient Bronsted acid catalyst under solvent-free conditions

The p -dodecylbenzenesulfonic acid (DBSA) has been successfully applied as an efficient acidic catalyst for the microwave-assisted synthesis of a series of 14-aryl- or alkyl-14 H -dibenzo[ a , j ]xanthenes ( 3a-m ) via a one-pot condensation-cyclization reaction of β -naphthol with various aliphatic or aromatic aldehydes under solvent-free conditions. Operational simplicity, short reaction times, excellent yields and environmentally-benign conditions are other advantages of this protocol.