Design and Synthesis of Novel Benzodiazepines

dc.contributor.authorMacQuarrie, Stephanie Leeen
dc.contributor.committeechairCarlier, Paul R.en
dc.contributor.committeememberLong, Timothy E.en
dc.contributor.committeememberKingston, David G. I.en
dc.contributor.committeememberDeck, Paul A.en
dc.contributor.committeememberTanko, James M.en
dc.contributor.departmentChemistryen
dc.date.accessioned2014-03-14T20:21:01Zen
dc.date.adate2006-01-05en
dc.date.available2014-03-14T20:21:01Zen
dc.date.issued2005-11-30en
dc.date.rdate2007-01-05en
dc.date.sdate2005-12-21en
dc.description.abstractBivalent drug design is an efficient strategy for increasing potency and selectivity of many drugs. We devised a strategy to prepare agonist-benzodiazepine heterodimers that could simultaneously bind to agonist and BZD sites of the GABAAR. We synthesized a benzodiazepine-MPEG model compound that relied on physiological GABA to elicit flux. We established that a tether at the N1 position of the BZD would not prevent binding to the receptor. However, coupling of GABA amides with long chain PEG tethers studied by another group member resulted in complete loss of agonist activity. We therefore ceased research in this particular area. 1,4-Benzodiazepin-2,5-diones display a wide range of pharmacological activities. Compounds containing the tricyclic proline-derived subtype have received attention as potent anxiolytic agents and as starting materials for anthramycin-inspired anticancer agents. More recently enantiopure (S)-proline-derived 1,4-benzodiazepin-2,5-diones have been recognized as selective α5 GABAA receptor ligands. Despite the impressive diversity of 1,4-benzodiazepine-2,5-diones prepared to date, enantiopure examples possessing a quaternary stereogenic center have been largely unexplored. "Memory of chirality" (MOC) is an emerging strategy for asymmetric synthesis. This technique enables the memory of a sole chiral center in the substrate to be retained in a process that destroys that center. We have used this technique to prepare a library of quaternary proline-derived, thioproline-derived and hydroxyproline-derived 1,4-benzodiazepin-2,5-diones, in high ee. We have developed an efficient synthetic method for preparing oxaproline-derived 1,4-benzodiazepin-2,5-diones in high yields, and by applying the MOC strategy we have prepared quaternary derivatives in acceptable %ee. We envision oxaproline-derived 1,4-benzodiazepin-2,5-diones may exhibit similar or more potent pharmacological properties than proline-derived 1,4-benzodiazepin-2,5-diones. Using density functional theory (DFT) methods, we modeled the formation of an enantiopure, dynamically chiral enolate intermediate and the slow racemization of the enolate on the alkylation reaction time scale.en
dc.description.degreePh. D.en
dc.identifier.otheretd-12212005-223136en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-12212005-223136/en
dc.identifier.urihttp://hdl.handle.net/10919/30209en
dc.publisherVirginia Techen
dc.relation.haspartetd.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject1,4-Benzodiazepin-1,5-dioneen
dc.subjectDensity Functional Theoryen
dc.subjectMemory of Chiralityen
dc.subjectAgonisten
dc.subjectAsymmetric Synthesisen
dc.subjectBenzodiazepineen
dc.subjectBivalent Liganden
dc.subjectGABA<sub>A</sub> Receptoren
dc.subjectHeterodimeren
dc.titleDesign and Synthesis of Novel Benzodiazepinesen
dc.typeDissertationen
thesis.degree.disciplineChemistryen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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