Synthesis, Characterization, Antimicrobial and Antioxidant Activities of The Homocyclotrimer Of 4-Oxo-4h-Thieno[3,4-C]Chromene-3-Diazonium Sulfate

Emmanuel Sopbue Fondjo*, a, Djeukoua Dimo Kamal Sorela, Tamokou Jean-de-Dieub, Tsemeugne Josepha, Kouamo Sylviana, Ngouanet Dorianea, Chouna Jean Rodolphea, Nkeng-Efouet-Alango Pepina, Kuiate Jules-Rogerb, Ngongang Ndjintchui Arnaudc, Sondengam Beibam Lucasd
a Laboratory of Applied Synthetic Organic Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, P.O. Box 67 Dschang, Republic of Cameroon
b Laboratory of Microbiology and antimicrobial Substances, Department of Biochemistry, Faculty of Science, University of Dschang, PO Box 067 Dschang, Republic of Cameroon
c Technical University of Munich, Department of Chemistry Lichtenbergstrasse 4, D-85747 Garching, Germany
d Department of Organic Chemistry, University of Yaounde I, P.O. Box 812 Yaounde, Republic of Cameroon

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 1692
Abstract HTML Views: 619
PDF Downloads: 404
ePub Downloads: 272
Total Views/Downloads: 2987
Unique Statistics:

Full-Text HTML Views: 716
Abstract HTML Views: 387
PDF Downloads: 302
ePub Downloads: 201
Total Views/Downloads: 1606

Creative Commons License
© Sopbue Fondjo et al.; Licensee Bentham Open.

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (, which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at the Laboratory of Applied Synthetic Organic Chemistry, Department of Chemistry, Faculty of Science, University of Dschang, P.O. Box 67 Dschang, Republic of Cameroon; Tel: +237 677822491; E-mail:


The in situ formed 4-oxo-4H-thieno[3,4-c]chromene-3-diazonium sulfate (5) in the coupling reactions involving the parent 2-aminothiophene (4) and various phenolic and arylamines’ couplers, readily undergoes homocyclotrimerization at low temperature to afford in fairly good yield the first ever reported eighteen member ring heteroaromatic holigomer 6. Compound 6 was fully characterized by its elemental analysis, IR, UV-Vis, 1H-NMR, 13C-NMR and HRMS spectral data. The HMBC and HSQC techniques were used to ascertain the structural assignments. A comparative study on the antimicrobial and antioxidant activities of compounds 3, 4 and 6 was carried out to assess the SAR due to the transformations (from 3 to 6 via 4) on the tested compounds. It was found that compounds 6 and 4 were respectively the most active compounds against bacteria (MIC = 32-64 μg/ml) and yeasts (MIC = 16–64 μg/ml). Compound 6 also showed high radical-scavenging activities and ferric reducing power when compared with vitamin C and BHT used as reference antioxidants.

Keywords: 2-aminothiophene, Azo compounds, Antimicrobial, Antioxidant, Coumarin, Homocyclotrimerization, Holigomer, SAR.