An efficient, clean synthesis of 3,3′-(arylmethylene)bis(2-hydroxynaphthalene-1,4-dione) derivatives

A clean, simple and efficient method for the synthesis of 3,3′-(arylmethylene)bis(2-hydroxynaphthalene-1,4-dione) derivatives has been developed which uses the reaction of 2-hydroxynaphthalene-1,4-dione and aromatic aldehydes in the presence of a catalytic amount of LiCl in aqueous media. To the best of our knowledge, this is the first report on such a synthesis of 3,3′-(arylmethylene)bis(2-hydroxynaphthalene-1,4-dione).