SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDY OF SOME NOVEL FLUORINE BASED 2-AMINOTHIAZOLES
Objectives: To synthesize, characterize and evaluate antimicrobial properties of some novel fluorine based 2-aminothiazoles.
Methods: The syntheses of some novel fluorine based 2-aminothiazoles have been described by using hypervalent iodine [I(III)] mediated approach. It was observed that this is the more general and promising method for the synthesis of any thiazole, but, when other methods work, the hypervalent iodine [I(III)] mediated approach generally gives better yields. The structures of these compounds have been characterized from the rigorous analysis of their IR, 1H NMR, MS and elemental analysis. These compounds were screened for their anti-microbial activity.
Results: The results revealed that compounds 7d, 7f, 10a, 10b, 10c, 14e and 14f showed moderate to good antibacterial activity as compared with the standard drug Chloramphenicol.
Conclusion: The two thiazole synthetic methods described herein use readily available reagents and both of them are easily feasible, the hypervalent iodine mediated approach for the synthesis of title compounds is more significant because, in spite of the better yields, it avoids the use of highly toxic and lachrymatory Î±-halogenoketone, thereby being more eco-friendlier.
2. Schneider S, Endermann R, Metzger KG, Bremm KD. New 3-substituted cephalosporins, process for their preparation and their use as medicinal preparations. Eur Pat Appl EP477717.
3. Charles GB, David HJ, George B. Cephalosporin derivatives and their homologues. PCT Int Appl WO9204353.
4. Piotr B, Edward Z, Piotr G, Joanna C, Zofia S. Method for producing semisynthetic beta-lactam antibiotics. Pol PL154681.
5. Currie RB, Beutel RH. Preparation of aminothiazole. US2850504.
6. Eiji N, Osamu I, Satoru H, Noriko S, Masahaki O. New thiazole derivative and antimicrobial agent containing the same derivative. Jpn Kokai Tokkyo Koho JP04112890.
7. Rout MK, Pujari HK. Preparation of 2-Substituted-4-methyl-5-carbethoxythiazoles. Condensation of ethyl acetoacetate with substituted thioureas. J Am Chem Soc 1953;75(16):4057-8.
8. Singh JM. New compounds. possible anthelmintic thiazol-5-ylbenzimidazoles. iii. J Med Chem 1969;12(3):553-3.
9. Litvinov OV, Safonova AA, Chalaya SN, Kharchenko VG. Synthesis of bis(aminothiazolyl)methanes and their inhibiting effects on acetylcholinesterase. Pharm Chem J (Engl Trans) 1994;28:83-5.
10. Tanaka A, Sakai H, Motoyama Y, Ishikawa T, Takasugi H. Antiplatelet agents based on cyclooxygenase inhibition without ulcerogenesis. Evaluation and synthesis of 4,5-bis(4-methoxyphenyl)-2-substituted-thiazoles. J Med Chem 1994;37(8):1189-99.
11. Welch JT. Selective fluorination in organic and bioorganic chemistry (American Chemical Society, Washington); 1999. p. 3;b) Welch JT, Eswarakrishnan S. Fluorine in bioorganic chemistry; Wiley, New York; 1991. c) Hudlicky M, Pavlath AE. Chemistry of organic fluorine compounds II (American Chemical Society, Washington); 1995.
12. Sharma PK, Singh K, Dhawan SN, Singh SP. Synthesis and characterization of some novel 4-formyl pyrazolylthiazoles of potential medicinal interest using Vilsmeier-Haack reaction. Indian J Chem 2002;41A(10):2071-5.
13. Neil O, Karele B. J Org Chem USSR (Eng Trans) 1970;6:889.
14. Koser GF, Wattach RH, Troup JM, Frenz BA. Hypervalent organoiodine. Crystal structure of phenylhydroxytosyloxyiodine. J Org Chem 1976;41(22):3609-11.
15. Prakash O, Saini N, Goyal S. Hypervalent iodine in the synthesis of bridgehead heterocycles: novel and facile syntheses of 3-substituted-5,6-dihydroimidazo[2,1-b]thiazoles and 3-phenylthiazolo[3,2-a]benzimidazole from acetophenones using [hydroxy(tosyloxy)iodo]benzene. J Chem Soc Perkin Trans-I 1992. p. 707-9.
16. Katritzky AR, Rees CW. Comprehensive Heterocyclic Chemistry, (Pergamon Press); 1984. p. 294.
17. Hantzsch A, Weber HJ. Ueber Verbindungen des Thiazols (Pyridins der Thiophenreihe). Ber Dtsch Chem Ges 1887;20:3118-32.
18. Prakash O, Saini N, Sharma PK. [Hydroxy(tosyloxy)iodo]benzene: a useful hypervalent iodine reagent for the synthesis of heterocyclic compounds. heterocycles 1994;38(2):409-31. b) Koser GF. [Hydroxy(tosyloxy)iodo]benzene and closely related iodanes: the second stage of development. Aldrichimica Acta 2001;34(3):89-102.
19. Moriarty RM, Vaid RK, Koser GF. [Hydroxy(organosulfonyloxy)iodo]arenes in organic synthesis. Synlett 1990;7:365-83.
20. Koser GF, Relenyi AG, Kalos AL, Rebrovic L, Wattach RH. One-step. alpha.-tosyloxylation of ketones with [hydroxy(tosyloxy)iodo]benzene. J Org Chem 1982;47(12): 2487-9.
21. Mahajan DF, Bhosale JD, Bendre RS. Synthesis, characterization and plant growth regulator activity of some substituted 2-amino benzothiazole derivatives. J Appl Chem 2013;2(4):765-71.
22. Lin AJ, Kasinat S. Synthesis of 3-substituted 7-(3,3-dimethyl-l-triazeno)-10-methylphenothiazines as potential antitumor agents. J Heterocyclic Chem 1981;18:759-61.
23. Javali V, Jayachandran E, Shah R, Patel K, Sreenivasa GM. Synthesis, characterization and anthelmintic activity (perituma-posthuma) of fluoro substituted benzothiazole for biological and pharmacological screening. Int J Pharm Bio Sci 2010;1(3):1-8.