A versatile annulation route to primary-amino-substituted naphthyridine esters

Abstract

A straightforward four-step synthesis of primary-amino-substituted naphthyridine esters from commercially available cyano-pyridines was described. The route makes use of a condensation reaction between pyridinyl acetates with N,N-dimethylformamide dimethylacetal (DMF-DMA) to form ortho-cyano vinylogous carbamates. These intermediates can undergo facile cyclization with ammonium acetate in acetic acid to generate the corresponding naphthyridine esters in good synthetic yields. The synthesis of -primary-amino-substituted 7-azaquinoxaline was also described. © Georg Thieme Verlag Stuttgart · New York.