Syntheses of new pyridoxazines, benzoxa(thia)azines, and benzoxa(thia)azepines via cyclocondensation and elimination reactions between donors and acceptors

Abstract

Reaction of 3-amino-2-hydroxypyridine and 2-amino(thio)phenols with various selected π-acceptors are herein reported. Different modes of cyclization via elimination and/or condensation reactions were observed during the reaction of the donors with 3,4,5,6-tetrachloro-1,2-benzoquinone (CHL-o),2,3,5,6- tetrachloro-1,4-benzoquinone (CHL-p),2,3-dicyano-l,4-naphthoquinone (DCNQ) and 2-dicyanomethyleneindane-1,3-dione (CNIND). A series of pyridoxazines, benzoxa(thia)azines, benzoxa(thia)azepines has been synthesized in good yields. © 2005 Verlag der Zeitschrift für Naturforschung.