Abstract
Refluxing dimethyl acetylenedicarboxylate (DMAD) or 1,2-dibenzoylacetylene with isatin-3-thiosemicarbazone or isatin-3-thiocarbohydrazone in methanol produced 3-substituted oxindoles in good yields. Reaction of equimolecular amounts of 5,6-diamino-urasil-solfate, trans-(1R,2R)-diaminocyclohexane, and 3,4-diamino-1,2,4-triazol-5-methyl hydrochlorid with isatin in ethanol (85%) afforded tetracyclic ring systems and ring-opened products in mild reaction conditions.
The authors are thankful to the Islamic Azad University of Ghaemshahr for their support.