Synthesis of novel heterocycles: Oxazolo[4,5-b]pyridines and oxazolo[4,5-d]pyrimidines

Article abstract of DOI:10.1016/S0040-4039(00)88750-X

Novel purine isosters (title compounds) have been prepared by condensation of the appropriate o-hydroxyaminoazine with ethyl orthoformate; extension to other orthoesters and to benzyl thioacetimidate afford 2-alkyl substituted derivatives of these new fus