Green synthesis of trans-2-(4-chlorobenzoyl)-5-hydroxy-3-(aryl)-2,3-dihydrobenzofuran-4,7-diones

A green and efficient synthesis of trans-2-(4-chlorobenzoyl)-5-hydroxy-3-(aryl)-2,3-dihydrobenzofuran-4,7-diones has been achieved in excellent yield via a three-component one-pot condensation of 2-[2-(4-chlorophenyl)-2-oxoethyl)]isoquinolinium bromide with 2,5-dihydroxy-1,4-benzoquinone and aromatic aldehydes in the presence of catalytic amounts of choline hydroxide in water under reflux conditions. The salient features of this protocol are the short reaction time, the high yields and it does not involve any hazardous organic solvent.