Regioselective Metalation of Ortho-Aminopicolines Using the Pivaloyl Group as a Directing Group: Synthesis of Naphthyridines

Abstract

2-(1,3-Dioxan-2-yl)-3-methyl-4- and 2-chloro-3,4-dimethyl-5-pivaloylaminopyridines were prepared and converted to 1,6- and 1,7-naphthyridines via regioselective lithiation of the ortho-methyl group, reaction with 2,2-diethoxyacetophenone and subsequent acid-catalyzed cyclization.