Synthesis of 5H-thiazolo[2′,3′:2,3]imidazo[4,5-b]indole Fused Hybrid Structures via Copper-Catalyzed Sequential C-N Coupling Reactions
Main Article Content
Abstract
In this study, we developed a simple and efficient synthetic procedure to obtain novel imidazothiazole-indole fused hybrid compounds through sequential C-N coupling reactions using copper catalysts. The key reaction was performed between 5-bromo-6-(2-bromophenyl)imidazo[2,1-b]thiazole derivatives and various amines, allowing for a significant expansion of the structural scope of the products compared to the use of nitrile derivatives. Optimal reaction conditions were identified, employing the CuI/ethyl 2-oxocyclohexane-1-carboxylate catalyst system, providing high overall yields (76-85%). Using this method, we successfully synthesized four new compounds (7c-f). The structures of all compounds were confirmed by 1H-NMR and 13C-NMR spectroscopy. This work presents a valuable contribution to the field of heterocyclic chemistry, offering a practical and versatile approach for the synthesis of diverse imidazothiazole-indole hybrids with potential applications in medicinal chemistry and materials science.
Keywords:
Imidazothiazole-indole fused hybrids, sequential C-N coupling, copper catalysis, structural diversity, heterocyclic chemistry.
References
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[7] G. C. Moraski, N. Deboosere, K. L. Marshall, H. A. Weaver, A. Vandeputte, C. Hastings, L. Woolhiser, A. J. Lenaerts, P. Brodin, M. J. Miller, Intracellular and in Vivo Evaluation of Imidazo[2,1-B]Thiazole-5-Carboxamide Anti-Tuberculosis Compounds, PLoS One, Vol. 15, 2020, pp. e0227224, https://doi.org/10.1371/journal.pone.0227224.
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[9] M. F. Baig, V. L. Nayak, P. Budaganaboyina, K. Mullagiri, S. Sunkari, J. Gour, A. Kamal, Synthesis and Biological Evaluation of Imidazo[2,1-B]Thiazole-Benzimidazole Conjugates As Microtubule-Targeting Agents, Bioorg. Chem., Vol. 77, 2018, pp. 515-526, https://doi.org/10.1016/j.bioorg.2018.02.005.
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[11] X. Deng, X. Tan, T. An, Q. Ma, Z. Jin, C. Wang, Q. Meng, C. Hu, Synthesis, Characterization, and Biological Activity of a Novel Series of Benzo[4,5]Imidazo[2,1-B]Thiazole Derivatives As Potential Epidermal Growth Factor Receptor Inhibitors, Molecules, Vol. 24, 2019, pp. 682, https://doi.org/10.3390/molecules24040682.
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[13] A. M. Curry, D. S. White, D. Donu, Y. Cen, Human Sirtuin Regulators: The "Success" Stories, Front. Physiol., Vol. 12, 2021, pp. 752117, https://doi.org/10.3389/fphys.2021.752117.
[14] E. Hoffmann, J. Wald, S. Lavu, J. Roberts, C. Beaumont, J. Haddad, P. Elliott, C. Westphal, E. Jacobson, Pharmacokinetics and Tolerability of SRT2104, A First-In-Class Small Molecule Activator of SIRT1, After Single and Repeated Oral Administration in Man, Br. J. Clin. Pharmacol., Vol. 75, 2013, pp. 186-196, https://doi.org/10.1111/j.1365-2125.2012.04340.x.
[15] L. Fletcher, S. K. Joshi, E. Traer, Profile of Quizartinib for the Treatment of Adult Patients With Relapsed/Refractory FLT3-ITD-Positive Acute Myeloid Leukemia: Evidence to Date, Cancer Manag. Res., Vol. 12, 2020, pp. 151-163, https://doi.org/10.2147/CMAR.S196568.
[16] K. Kidoguch, M. Shibusawa, T. Tanimoto, A Critical Appraisal of Japan's New Drug Approval Process: A Case Study of FLT3-ITD Inhibitor Quizartinib, Invest. New Drugs, Vol. 39, 2021, pp. 1457-1459, https://doi.org/10.1007/s10637-021-01151-0.
[17] E. Gursoy, E. D. Dincel, L. Naesens, N. U. Guzeldemirci, Design and Synthesis of Novel Imidazo[2,1-B]Thiazole Derivatives as Potent Antiviral and Antimycobacterial Agents, Bioorg. Chem., Vol. 95, 2020, pp. 103496,
https://doi.org/10.1016/j.bioorg.2019.103496.
[18] G. C. Moraski, N. Seeger, P. A. Miller, A. G. Oliver, H. I. Boshoff, S. Cho, S. Mulugeta, J. R. Anderson, S. G. Franzblau, M. J. Miller, Arrival of Imidazo[2,1-B]Thiazole-5-Carboxamides: Potent Anti-Tuberculosis Agents That Target Qcrb, ACS Infect. Dis., Vol. 2, 2016, pp. 393-398, https://doi.org/10.1021/acsinfecdis.5b00154.
[19] S. Kumar Ritika, A Brief Review of The Biological Potential of Indole Derivatives, Future J. Pharm. Sci., Vol. 6, 2020, pp. 1-19, https://doi.org/10.1186/s43094-020-00141-y.
[20] S. Thomas, L. L. Kleintop, G. C. Prendergast, Reliable Detection of Indoleamine 2,3 Dioxygenase-1 in Murine Cells and Tissues, Methods Enzymol, Vol. 29, 2019, pp. 219-233, https://doi.org/10.1016/bs.mie.2019.08.008.
[21] M. Stiborova, J. Poljakova, E. Martinkova, L. B. Dohalska, T. Eckschlager, R. Kizek, E. Frei, Ellipticine Cytotoxicity to Cancer Cell Lines - A Comparative Study, Interdiscip. Toxicol., Vol. 4, 2011, pp. 98-105, https://doi.org/10.2478/v10102-011-0017-7.
[22] P. Dhyani, C. Quispe, E. Sharma, A. Bahukhandi, P. Sati, D. C. Attri, A. Szopa, J. S. Rad, A. O. Docea, I. Mardare, D. Calina, W. C. Cho, Anticancer Potential of Alkaloids: A Key Emphasis to Colchicine, Vinblastine, Vincristine, Vindesine, Vinorelbine and Vincamine, Cancer Cell Int., Vol. 22, 2022, pp. 206, https://doi.org/10.1186/s12935-022-02624-9.
[23] H. M. Sampath Kumar, L. Herrmann, S. B. Tsogoeva, Structural Hybridization as a Facile Approach to New Drug Candidates, Bioorg. Med. Chem. Lett., Vol. 30, 2020, pp. 127514, https://doi.org/10.1016/j.bmcl.2020.127514.
[24] O. M. Soltan M. E. Shoman, S. A. A. Aziz, A. Narumi, H. Konno, M. A. Aziz, Molecular Hybrids: A Five-Year Survey on Structures of Multiple Targeted Hybrids of Protein Kinase Inhibitors for Cancer Therapy, Eur. J. Med. Chem., Vol. 225, 2021, pp. 113768, https://doi.org/10.1016/j.ejmech.2021.113768.
[25] S. Sharma, R. Das, M. Jadhav, A. Shard, Thiazole as an Indispensable Scaffold in Anti-Leukemic Agents: A Semicentennial Review, Chemistryselect, Vol. 9, 2024, pp. e202400879, https://doi.org/10.1002/slct.202400879.
[26] A. Singh, D. Malhotra, K. Singh, R. Chadha, P. M. S. Bedi, Thiazole Derivatives in Medicinal Chemistry: Recent Advancements in Synthetic Strategies, Structure Activity Relationship and Pharmacological Outcomes, J. Mol. Struct., Vol. 1266, 2022, pp. 133479, https://doi.org/10.1016/j.molstruc.2022.133479.
[27] P. Bhaumick, R. Kumar, S. S. Acharya, T. Parvin, L. H. Choudhury, Multicomponent Synthesis of Fluorescent Thiazole–Indole Hybrids and Thiazole-Based Novel Polymers, J. Org. Chem., Vol. 87, 2022, pp. 11399-11413,
https://doi.org/10.1021/acs.joc.2c00922.
[28] P. K. Adhikary, S. K. Das, B. A. Hess, Jr., Synthesis, Antihypertensive Activity of Some Imidazoindole Derivatives, J. Med. Chem., Vol. 19, 1976, pp. 1352-1354, https://doi.org/10.1021/jm00233a022.
[29] C. H. Kim, Y. M. Baek, H. Ch. Park, Ch. J. Lee, J. Y. Shin, J. H. Lee, H. S. Jo, Preparation of Condensed Imidazoindole Compounds as Organic Electroluminescent Device, Patent, KR20150034029A, 2015.
[30] S. Khan, V. Bajpai, H. M. Gauniyal, B. Kumar, P. M. Chauhan, Skeletal Diverse Synthesis of N-Fused Polycyclic Heterocycles Via the Sequence of Ugi-Type MCR and Cui-Catalyzed Coupling/Tandem Pictet-Spengler Reaction,
J. Org. Chem., Vol. 77, 2012, pp. 1414-1421, https://doi.org/10.1021/jo202255v.
[31] Y. Saito, H. Ishitani, M. Ueno, S. Kobayashi, Selective Hydrogenation of Nitriles to Primary Amines Catalyzed By A Polysilane/SiO2-Supported Palladium Catalyst Under Continuous-Flow Conditions, ChemistryOpen, Vol. 6, 2017, pp. 211-215, https://doi.org/10.1002/open.201600166.
[32] N. Disney, M. Smyth, S. Wharry, T. S. Moody, M. Baumann, A Cyanide-Free Synthesis of Nitriles Exploiting Flow Chemistry, React. Chem. Eng., Vol. 9, 2024, pp. 349-354, https://doi.org/10.1039/d3re00458a.
[33] H. N. Do, N. M. Quan, B. V. Phuc, D. V. Tinh, N. Q. Tien, T. T. T. Nga, V. T. Nguyen, T. Q. Hung, T. T. Dang, P. Langer, Efficient Copper-Catalysed Synthesis of Carbazoles By Double N-Arylation of Primary Amines With 2,2′-Dibromobiphenyl in the Presence of Air, Synlett, Vol. 32, 2021, pp. 611-615, https://doi.org/10.1055/s-0040-1706641.
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