A concise metal-free synthesis of xanthene derivatives mediated by achiral 2-aminophenol under solvent-free conditions

An efficient green technique has been developed for the synthesis of some biologically active 12-aryl or 12-alkyl 8,9,10,12-tetrahydrobenzo[a]xanthenes-11-one and 3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione derivatives have been described. This process arranged a three-component one-pot condensation of aldehydes, 2-naphthol, and dimedone mediated by 2-aminophenol and has offered an excellent scope of tailoring a large number of xanthene derivatives with good to charming yields. Short reaction time, straightforward, easy product isolation technique, non-toxic catalyst, and above all metal-free process are noteworthy advantages of this method.