Synthesis of 2,6-di(1,8-naphthyridin-2-yl)pyridines functionalized at the 4-position: Building blocks for suitable metal complex-based dyes

This study reports the synthesis of a methoxy-substituted 2,6-di(1,8-naphthyridin-2-yl)pyridine using Friedländer methodology. The functionalization at the 4-carbon of the methoxy-substituted derivative was confirmed by X-ray structural analysis. Finally, the methyl ether protecting group was cleaved to obtain 2,6-di(1,8-naphthyridin-2-yl)pyridine-4-ol. Using the compounds, coordination behavior to ruthenium(II) center was also examined.