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BY-NC-ND 3.0 license Open Access Published by De Gruyter June 2, 2014

Synthesis of New 2-Substituted 6-Bromo-3-methylthiazolo[3,2-a]- benzimidazole Derivatives and their Biological Activities

Hatem A. Abdel-Aziz, Nehal A. Hamdy, Amira M. Gamal-Eldeen and Issa M. I. Fakhr

1-(6-Bromo-3-methyl-1,3-thiazolo[3,2-a]benzimidazol-2-yl)ethanone (2) was prepared by bromination at ambient temperature of 1-(3-methylthiazolo[3,2-a]benzimidazol-2-yl)ethanone (1). The structure of 2 was determined by single-crystal X-ray diffraction. The precursor 5 was synthesized by heating a mixture of acetyl 2 and bromine. Various 2-substituted 6-bromo-3-methylthiazolo[3,2-a]benzimidazoles containing 1,3-thiazole, 1,4-benzothiazine, quinoxaline or imidazo[1,2-a]pyridine moieties were prepared starting from bromoacetyl 5. Taken together from the biological investigations, 2, 5, and 7a were potent immunosuppressors against both macrophages and T-lymphocytes, and 7b, 11b, and 14 were potent immunostimulators towards both types of immune cells. The results also revealed that, among others, 2 and 14 were the most signifi cant inhibitors of LPS-stimulated NO generation, and that 5, 7a, and 7b had a weak radical scavenging activity against DPPH radicals. Moreover, 2, 5, and 7a had a concomitant strong cytotoxicity against colon carcinoma, hepatocellular carcinoma, and lymphoblastic leukemia cells. Collectively, compounds 2, 5, and 7a are multipotent compounds with promising biological activities.

Received: 2009-4-9
Revised: 2010-8-3
Published Online: 2014-6-2
Published in Print: 2011-2-1

© 1946 – 2014: Verlag der Zeitschrift für Naturforschung

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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