Neighbouring Group Participation in Formation of Condensed Azines. Formation of Pyrazolo(3,4-b)pyrazines, Isoxazolo(4,5-b)pyrazines and Isothiazolo(5,4-b)pyridine (Heterocycles, CCX)

Article abstract of DOI:10.1007/BF00809014

Pyrazine- and pyridinecarboxamidoximes with an amino, potentially tautomeric hydroxy or mercapto group in ortho position could be transformed in the appropriate condensed azines.In this manner, representatives of pyrazolo(3,4-b)pyrazine, isoxazolo(4,5-b)pyrazine and isothiazolo(5,4-b)pyridine ring system were synthesized and some transformations investigated. - Keywords: Cyclization with N-N, N-O or N-S bond formation; Heterocyclic compounds