A simple reaction of some oxindole derivatives with 1,2-diaza-1,3-dienes to produce 2-oxo-spiro[indole-3,4′-pyridines] in good yields is described here. This transformation represents a practical two steps approach to new and biologically interesting 2-oxo-spiro[indole-3,4′-pyridine] scaffolds using a double Michael addition/cyclization sequence.
![Graphical abstract: Synthesis of novel symmetrical 2-oxo-spiro[indole-3,4′-pyridines] by a reaction of oxindoles with 1,2-diaza-1,3-dienes](http://hg.y866.cn/compound/lib/scimg/usr/1/C4OB01959H.jpg)