Structural study involving 9-(pyrid-2-yl)indolizine-1-one and related derivatives of dipyridyl methanol

Abstract For the first time, the synthesis of 9-(pyrid-2-yl)indolizine-1-one from dipyridylpropargyl alcohol together with its molecular structure is reported. As the racemate was used for crystallization, the asymmetric unit contains both enantiomers. The molecular conformation of the pyridyl indolizinone scaffold of the title compound is similar to the one found for the respective chlorophenyl substituted derivative. Furthermore, we report here on the synthesis and X-ray structures of two alkylated dipyridyl methanols, which have been recovered in connection with the synthesis of the indolizinone. Both prochiral alcohols show conformational chirality in the solid state. In both compounds, intramolecular O–H … N pyridine hydrogen bonds stabilizing their molecular conformation are typical. As a common packing motif, we found a O–H⋯N bonding system featuring the graph set descriptor R 2 2 ( 10 ) . With reference to the structural relationship that can be found between pharmaceutically interesting agents and title compounds, the presented molecules are promising models for future drug design.