Multicomponent synthesis of 4-unsubstituted 5-nitropyridine derivatives

Abstract

Multicomponent reaction of 2-nitroacetophenone, urotropine (or paraformaldehyde), β-dicarbonyl compound and ammonium acetate afforded five new 4-unsubstituted 5-nitro-6-phenyl-1,4-dihydropyridine derivatives, oxidation of which provided the corresponding 5-nitro-6-phenylpyridines. The proposed approach for the synthesis of 4-unsubstituted 5-nitro-6-phenyl-1,4-dihydropyridines and their subsequent aromatization into pyridines made it possible to reduce the total reaction time by more than 200 times and the overall yield of 5-nitro-6-phenylpyridine by 2 times compared with the known methods.

Graphical Abstract

Keywords:

• Green chemistry
• 5-nitro-1,4-dihydropyridines
• 5-nitropyridines
• multicomponent reaction

Acknowledgments

Spectrophotometric studies were performed on the basis of the Research Resource Center “Natural Resource Management and Physico-Chemical Research” Institute of Chemistry, Tyumen State University (with the financial support of the Ministry of Science and Higher Education of the Russian Federation (contract no. 05.594.21.0019, unique identification number RFMEFI59420X0019)).

Additional information

Funding

The reported study was funded by RFBR according to the research project [No. 19-03-00376].