Universität Tübingen
Synthesis and Characterisation of Novel Cationic Imidazolium Derivatives - on the Route to Possible Drugs
Abstract
The object of this work is to clarify nucleophilic properties of diaminocarbenes. New different types of 2,3-dihydroimidazole-2-ylidenes have successfully synthesized on the route to possible drugs. The resulting compounds are classified into nucleophilic aromatic substitution, imidazolium aryl oxide and salt derivatives. The carbon-fluorine bond is commonly found in pharmaceuticals, fluorine-containing aromatics have been incorporated into drugs (analgesic, antibacterial). Recently, nucleophilic aromatic substitution of haloarenes with different nucleophilic center became very important, SNAr reactions of polyfluoroaromatic compounds occur via an addition-elimination mechanism. We are interested to obtain more information on the scope of such reactions, we have now investigated that 1,3-diisopropyl-4,5-dimethyl-4,5-dimethylimidazol-2-ylidene attack polyfluoroaromatic compounds in which fluoride displaced by the carbene carbon to afford different types of imidazolium adducts. Stable imidazolium alcoholates have been synthesized in good yield. As expected, 1,3-diisopropyl-4,5-dimethyl-4,5-dimethylimidazol-2-ylidene was reacted readily with phenol, pentachlorophenol and pentafluorophenol in diethyl ether from which the imidazolium salts precipitated as stable colourless salts. Other imidazolium salts containing ion pairs linked by hydrogen bonds have been determined by X-ray analyses. The C-H…X (X = O, S, N) hydrogen bonds may act as an additional stabilizing factor in their crystal structures, these compounds play an important role in the construction of ionic liquids, which can be potentially used as pharmaceutical solvents.
Author and committee
dc:creator, dc:contributor.*- Author
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- Mallah, Eyad
Identifiers
dc:identifier.*- Identifier
- hdl:10900/49298