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

Abstract

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.

Graphical Abstract

KEYWORDS:

• Crystal structure
• Friedländer condensation
• naphthyridine
• polypyridine
• ruthenium complex

Acknowledgments

We would like to thank Dr. Kyeonga Inomata at Tohoku University for HRMS measurements of 2d and Rigaku Corporation for the X-ray measurement of the Ru-complex.

Additional information

Funding

This work was supported by Japan Society for the Promotion of Science (JSPS) under [Grant JP17K05799].