Abstract
Here in, we described the synthesis of novel bisheterocycles imidazopyridine bearing xanthenedione by reacting various substituted 2-phenylimidazo [1,2-a] pyridine-3-carbaldehyde with cyclohexane-1,3-dione in gluconic acid aqueous solution (GAAS) via a tandem Knoevenagel followed by Michael, cyclization & tautomerization sequence. The use of GAAS in organic synthesis offers significant benefits like cost-effective, simple operation, reusable catalyst and green method. The reaction completed in 2–12 h to afford white stable solid compounds with very good yield. The structures of the compounds are confirmed by analyzing MS, IR, 1H NMR and 13C NMR spectra. Further, the structure of compound 3 h was confirmed by XRD analysis.
GRAPHICAL ABSTRACT
![](/cms/asset/bb33bc2a-e458-41c3-9401-a4ff83eabeaa/lsyc_a_1606920_uf0001_c.jpg)
Acknowledgments
The authors are thankful to Dr. S. J. S. Flora, Director for his support in carrying out this research work. The authors would like to acknowledge Department of Pharmaceuticals, Ministry of Chemicals and Fertilizers, Govt. of India for financial support, SAIF, CSIR-CDRI, Lucknow for the spectral analysis and Indian Institute of Technology, Kanpur for single crystal X-ray analysis.
Supporting information
Full experimental detail, ESI-MS; HRMS, 1H and 13C NMR spectra of all compounds and XRD data of 3 h can be found via the “Supplementary Content” section of this article’s webpage.