A novel synthesis of 2-arylhydrazono-6-amino-4-arylbenzene-1,3-dicarbonitriles and their conversion into phthalazines

Compounds 1a–d react with benzylidenemalononitrile 2 to yield dihydroaminopyridazines 3a–d and, in contrast, compounds 1e,f react with 2 under the same conditions to yield aminobenzenedicarbonitriles 8e,f compound 8e underwent intramolecular cyclization to phthalazine 9e. Compound 10e reacted with 2a to yield 11e.