Seven Membered Rings with Three Heteroatoms 1,2,4

YRANZO, G. I.; MOYANO, E. L.

Comprehensive Heterocyclic Chemistry III

Elsevier

Año: 2006;

Chapter 12.14 covers the literature on 7-membered rings with three heteroatoms 1,2,4. The heterocycles that were studied are monocyclic and fused triazepines, monocyclic and fused oxadiazepines and monocyclic and fused thiadiazepines. The different articles cover: theoretical calculations of conformations and tautomerism;  thermodynamic measurements of gas-phase basicity, spectroscopic studies of tautomerism; and crystal structure determinations. There were also many articles on the synthesis of these heterocycles from different starting materials. For example starting from acyclic compounds such as bis-acetylenic ketones and thiosemicarbazides and from other heterocycles such as azoles (monocyclic and fused), thienopyrimidines,  tetrahydroquinazolines and tetrahydroquinazolines. Besides, reactions of these heterocycles with different compounds, such as: 2-haloketones, trimethyloxosulfonium iodide, nucleophiles and electrophiles are also described. Finally, the biological activity as immunosuppressants to control cancer associated with the hyperimmune system, such as leukaemia and lymphoma is described.