Acylation of aminopyridines and related compounds with endic anhydride

Reactions of bicyclo[2.2.1]hept-5-ene-endo-2,endo-3-dicarboxanhydride (endic anhydride) with 2-, 3-, and 4-aminopyridines, 3-hydroxy- and 5-iodo-2-aminopyridines, 6-aminoquinoline, and 6-aminoquinoxaline involve chemoselective transformation of the exocyclic amino group. The resulting amido acids were converted into the corresponding carboximides, and the latter were epoxidated with peroxy acids. The structure of the products was confirmed by the IR, UV, and H-1 and C-13 NMR spectra, as well as by calculation of the H-1 and C-13 chemical shifts using the GIAO method (B3LYP/6-31G** approximation).