Synthesis of some novel 2-phenylpyridazino[4,5-b][1,5]thiazepines

Article abstract of DOI:10.1002/jhet.5570330309

Synthesis of some derivatives of the pyridazino[4,5-b][1,5]thiazepine ring system is reported. Thus, 5-benzyl-8-methyl-2-phenyl-2,3,4,5-tetrahydro-5H-pyridazino[4,5-b][1,5] thiazepin-9(8H)-one (5) was prepared by an intramolecular S-alkylation reaction, whereas the thiazepine ring of sulfone analogue 21, and that of the novel tricyclic pyrrolidino fused ring system 22 was elaborated by an intramolecular C-alkylation reaction. Unexpected formation of bicyclic pyrido- and thiazine fused pyridazine systems are also discussed.