Heterocyclic studies: New heterocyclic ring systems from isomeric dimethyl diaminophthalates

The synthesis and reactions of dimethyl 3, 4- and 4, 5-diaminophthalate 7 and 9 were investigated. The condensation of these isomeric diaminophthalates and their respective nitroacetamido precursors have been shown to give rise to a variety of five, six and seven membered heterocyclic ring system. Several new tetraazanthracenes have also been prepared in this sequence.