STUDIES OF OXAZOLE , BENZIMIDAZOLE, OXADIAZOLE AND RELATED COMPOUNDSTHESIS SUBMITTED TO THE UNIVERSITY OF MUMBAI FOR THE DEGREE OF DOCTOR OF PHILOSOPHY FACULTY OF SCIENCE (ORGANIC CHEMISTRY) PATKAR COLLEGE 2008
SYNOPSIS OF THE THESIS TO BE SUBMITTED TO THE UNIVERSITY OF MUMBAI FOR THE DEGREE OF DOCTOR OF PHYLOSOPHY IN THE FACULTY OF SCIENCE (ORGANIC CHEMISTRY) NAME OF THE STUDENT : VIBHA JAGDEVPRASAD PANDEY TITLE OF THESIS :“STUDIES IN OXAZOLE, IMIDAZOLE, BENZIMIDAZOLE AND RELATED COMPOUNDS”. NAME AND DESIGNATION : Dr.UDAY C. MASHELKAR M.Sc. Ph.D. THE OF GUIDING TEACHER PRINCIPAL, PATKAR COLLEGE, GOREGAON (W) PLACE OF RESEARCH : ORGANIC RESAERCH LABORTORY. PATKAR COLLEGE, GOREGOAN (W). NUMBER AND DATE OF : 17 / 6th DECEMBER 2005 REGISTRATION DATE OF SUBMISSION OF : 20th DECEMBER 2007
Compounds based on coumarin and chromone ring system are one of the most extensively investigated and commercially significant groups of organic compounds. In recent years coumarin containing crown ethers and macrocyclic systems has been exploited in the area of metal ion sensors1 and number of these product shows marked physiological impact2. In addition coumarins are also of considerable biological and medicinal interest. It is found that coumarin plays important role in enzymatic oxidation3 and shows antioxidative, perioxidative effect4.
Nitrogen containing heterocycles being another important group of heterocycles5, these compounds are widely distributed in nature. These compounds playing a vital role in the metabolic activity of all living cells e.g. the pyrimidine and purine bases of the genetic materials; the essential amino acids; the vitamins and coenzymes. Imidazole and benzimidazole are the important group of compounds6. Benzimidazoles are known to have varied biological activity and among them 2- substituted benzimidazolees are found to be more potent.7 Owing to the importance of these systems in pharmacological, commercial, analytical and industrial applications; it’s significant to design and synthesize novel heterocycles of these classes. Keeping this in mind, we targeted to synthesize coumarin with benzimidazole, benzisooxazole, oxazole and oxodiazole as substitution at four position of coumarin. At the same time these substitutions were attached with chromone ring. As wide application of chromone and coumarin were seen in the host-guest chemistry and metal ions sensors8. We synthesized some of the coumarin and chromone based podands and their complexes with transition metal ions. Podands are linear multidentate legands. These podands are similar to salen and smdpt9. The synthetic strategy employed for the purpose is summarized below.
Chromone aldehyde and coumarin aldehydes were prepared as per the literature10, from phenols by Pechmann condensation and Vilsmeier-Hack reaction11. These aldehydes were condensed with hydrazides of isooxazole 2-acetic acid esters, and subsequent cyclization in acidic medium gives the desired oxadiazole derivatives. Another synthetic route employed the alkylation of imidazole with chloroethylacetate their hydrazide formation. Furthermore the podands were prepared from Ethylenediamine and o- phynelenediamine (OPDA) to yield salen and smdpt type of compound. Complexes of these ligands with transition metal ions were studied. This work is presented through five chapters.
Chapter one is introductory in nature dealing with coumarins, imidazoles, isooxazoles and oxadiazoles, their general method of synthesis, characterization and reactions that lead to modified and highly functionalized compounds, their applications in various fields of interest. Chapter two and three deals with theoretical and experimental part of synthesis leading to coumarin and chromone derivatives with imidazole, oxazole, oxadiazole. Chapter four is about the tweezers and ligands synthesis of benzimidazole, oxazole and chromene. Chapter five is regarding the application part of synthesized molecule i.e. complexation studies of the ligands with transition metals and their biological activity.
O OH OHR R O O (1) N O N H R R O O O O (3) (2) Scheme-1
N N N N N N H H O N NH 2R R O R O O O O O O O (3) N N N N N H N N NR O O O R O O O R, (4) R, Scheme-2
O O O R O R OR O O (3) + N N O OH O O N O N H O (5) R, Scheme-3
O OH N O N N N O O N N N H H H N N N O O O(6) (7) (8) Scheme-4
N N N N N N H N O N N OO O O HN (6) O NH2 N N N N R R N O N NO N O O HN N O O (9) O O Scheme-5
O O O OH O NH2 NH N N O N O O R N N O O O O O N N N O HO N R O (10) Scheme-6
OH HO O O AcO O O HO O HO O O HO O O O O O O O O O O O OO O O O O O O O O (13) (14) (11) (12) OH OH O O O HO HO HO (15) O O O HO (16) Scheme-7
O O N O ONH O + O O O ONH N O [(11), (2), (14), (16)] O O O (17) O O O O N NH O O O O + O N NH O O [(11), (2), (14), (16)] (18) Scheme- 8
REFERENCES: Valeur B. Habib Jivan J.L. J. Photoch. Photobio. A 116, 127,(1998). Miyake. Joshi. J. Agri. Food. Chem. 48(8), 3151, (1999). Swain C. G., Thripathy P. C., Ind. J. Plant. Physiology. I4(3), (1999), 157. Liu Z. Q., Yu. W., Chem. Phy. Lipids, 103(1,2), 125 (1999). Grimmet. M. R, “Comprehensive Heterocyclic Chemistry”, Potts.K.T.(Ed), Katrizky. A.R. & Rees. K. W.(Gen.Eds.), Pergamon Press, Oxford, Vol.5, Chapter 4, 457, (1984). Preston P. N. Chem. Rev., 74, 279, (1974). Preston P. N (ED) “Benzimidazoles and Congeneric Tricyclic Compounds”, (Wiley Interscience, New York) Part2, Chapter 10, 531 (1980). a) Willem. Verboom David N. Reinhoudt, Chem. Soc. Perkin. Tran 2. 135 (1995). b) Tyagi et.al. I.J.C. vol.78, 251 (2001). Ind. Ac. Sci. A. 567 (1938). Sethna. Sm, Shah R.C. J. Chem. Soc. 228., (1938). Horning, E. C. in Organic synthesis, Vol. III, Wiley, New York, 281(1955).
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