Synthesis of derivatives of a novel heterocyclic system 7-thia-1,4,6,8-tetraazabenzo[de]anthracene

 Derivatives of a novel heterocyclic system, 8,9,10,11-tetrahydro-7-thia-1,4,6,8-tetraazabenzo[de]anthracene, were obtained by interaction of 5Н-pyrido[2′,3′:2,3]thiopyrano[4,5-b]pyridines, formed by treating N-methylmorpholinium 4-aryl-3-cyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates with malononitrile dimer, Ас2О or carboxylic acid chlorides.