Heterogeneous catalytic oxidation of pyridines to N-oxides under mild conditions using tungsten-loaded TiO2 was written by Li, Qing-Feng;Luo, Wen;Lu, Wei;Wang, Zhenling. And the article was included in Reaction Kinetics, Mechanisms and Catalysis in 2016.Electric Literature of C7H9NO This article mentions the following:
The heterogeneous catalytic oxidation of pyridines to pyridine N-oxides has been studied using tungsten-loaded TiO2 as the catalyst and hydrogen peroxide as the green oxidant. The catalysts were synthesized by a simple impregnation technique and characterized by X-ray powder diffraction, Raman spectroscopy, transmission electron microscopy, energy dispersion X-ray spectroscopy, XPS. The catalytic performances of the catalysts were evaluated by the N-oxidation of pyridines with 30 weight% H2O2 solution as an environmentally friendly oxidant at room temperature These processes serve as an efficient method to prepare a variety of pyridine-N-oxides in modest to high yields, and the pyridine N-oxides could be easily separated from the heterogeneous catalytic system. This study will provide a useful strategy for preparation of heterocyclic N-oxides in the mild condition. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Electric Literature of C7H9NO).
3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Electric Literature of C7H9NO