Azetidine and cyclopropylamine in the “1,2,4-triazine” methodology for the synthesis of α-functionalized 2,2′-bipyridines

Functionalization of 3-(2-pyridyl)-1,2,4-triazines with small (aza)cyclic compounds (azetidine and cyclopropylamine) via nucleophilic ipso-substitution of the cyano group and subsequent transformation of the 1,2,4-triazine ring into pyridine one via the aza-Diels—Alder reaction were explored. The successful proceeding of such a transformation depended on the structure of the nucleophilic residue: both steps were successfully implemented upon using a cyclopropylamine derivative, while in the case of azetidine-containing 1,2,4-triazines, there was only the resinification of the reaction mass.