The goal of this project is to synthesize and purify a library of novel 4-alkyl-3,5-diamino-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazoles. These molecules are similar to other fiproles, which have been shown by Sammelson et al. to have pesticidal activities at the GABA receptor.' Fiproles are analogues of Fipronil, a very important pesticide. Replacing the cyano group normally located at the 3-position of the pyrazole ring with an amino group will change the binding potency of the phenylpyrazoles. Changes in binding produced by the changes introduced in molecular structure can create more information about the GABA receptor.Synthesis of our target compounds starts with production of monosubstituted malononitriles. Conventionally a two-step process, our research developed a new, efficient one-step process using borohydride as the only reagent. We utilized this method in the synthesis of desired monosubstituted malononitriles. These were converted to unsymmetrical disubstituted malononitriles, and to our target fiprole compounds, through a 4-alkyl-3,5-diaminopyrazole intermediate. / Department of Chemistry

Thesis (Ph. D.)--University of Hawaii at Manoa, 1995. / Includes bibliographical references (leaves 124-127). / Microfiche. / xi, 127 leaves, bound ill. 29 cm

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 87-92). / viii, 92 leaves, bound ill. 29 cm

The primary aim of this project was to synthesize new heterocyclic dimers of isoflavones and flavones, and investigate various methodologies for their synthesis. The secondary aim of the project was to synthesize some flavonoid natural products. Dimeric systems were synthesized using various methodologies including acid catalyzed arylation of isoflavanols and flavanols, acid catalyzed dimerization of flavenes, oxidative dimerization, Sonogashira coupling, Ullmann coupling and Suzuki-Miyaura coupling reactions. The acid catalyzed arylation of isoflavanols was found to proceed in a very stereoselective fashion to give trans-4-arylisoflavans in good yield in a single step. However, related flavanols under similar conditions gave mixtures of cis and trans isomers of 4-arylflavans. Interestingly, it was found that appropriately substituted flavenes, upon treatment with acid undergo stereoselective rearrangement and dimerization to give benzopyranobenzopyrans in high yields. A rationale for the rearrangement is proposed and this dimerization was used for the stereoselective synthesis of the natural product dependensin. As part of the project, some polycyclic natural products such as octandrenolone, flemiculosin, 3-deoxy-MS-II and laxichalcone were also synthesized. Oxidative dimerization of activated isoflavones was found to be very regioselective, and novel isoflavone dimeric systems were synthesized. Related flavones however, failed to undergo dimerization under similar conditions. A probable explanation for high regioselectivity in the case of isoflavones and unreactivity of flavones has been presented. Phenol oxidative coupling was used for the one-step synthesis of another natural product kudzuisoflavone-A from daidzein. Sonogashira coupling was utilized for the synthesis of dimeric systems linked via an acetylic linker. A variety of soflavone isoflavone, flavone-flavone and isoflavone-flavone dimers were synthesized in "one-pot" by this methodology and in excellent yields. Although Ullmann coupling was found not to be suitable for the synthesis of isoflavone or flavone dimers, one-pot Suzuki-Miyaura methodology gave flavone dimers and various other heterocyclic dimers in good yields.

Bibliography: leaves 159-164. / iv, 158 leaves ; 30cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis examines routes for the asymmetric synthesis of three members of the nonsteroidal anti-inflammatory class of drugs (NSAIDs) The aryl propanoic acid ibuprofen is synthesized in 96% e.e. Control of stereochemistry is achieved by use of the Sharpless epoxidation reaction, followed by reduction of the product epoxide by complex hydride with assistance by titanium tetraisopropoxide acting as a Lewis acid. The final step is the coupling of an optically active carboxylic acid intermediate with the iso-butyl side chain to give (S)-ibuprofen. / Thesis (Ph.D.)--University of Adelaide, Dept. of Organic Chemistry, 1997?

Bibliography : leaves 198-204. / vi, 204 leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Organic Chemistry, 1992

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