The synthesis and properties of naphthodifuranones and naphthofuranonepyrrolidones

Benzodifuranones were modified by the replacement of central benzene nucleus with naphthalene moiety. Such modified structures offer the possibility of extension into the blue colour shade range. Symmetrically disubstituted naphthodifuranones were synthesised by the reaction of 1,5-dihydroxynaphthalene with an appropriate mandelic acid. Asymmetrically mono and disubstituted naphthodifuranones were synthesised by the reaction of the halfcondensed intermediates with appropriate mandelic acids. Symmetrical naphthofuranonepyrrolidones were synthesised by the reaction of 1-amino-5hydroxynaphthalene with an appropriate mandelic acid.