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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Photo-active anthracene receptors for s-block and d-block metals

McSkimming, Gordon January 2001 (has links)
No description available.
152

Total synthesis of 6-chlorodemethyllavendamycin esters and amides

Chenault, Darrell Vincent January 1998 (has links)
The synthesis of several 6-Chlorodemethyllavendamycin analogs and their chemistry are described. In this investigation the following compounds were prepared:6-Chlorodemethyllavendamycin methyl ester, 6-Chlorodemethyllavendamycin ethylester, 6-Chlorodemethyllavendamycin butyl ester, 6-Chlorodemethyllavendamycin isoamyl ester, 6-Chlorodemethyllavendamycin octyl ester, and 6-Chlorodemethyllavendamycin amide. Pictet Spengler condensation of 7-amino-6-chloro-2-formylquinoline-5,8-dione with tryptophan methyl ester, tryptophan ethyl ester, tryptophan butyl ester, tryptophan isoamyl ester, tryptophan octyl ester, and tryptophan amide in anisole afforded the compounds. 7-amino-6-chloro-2-formylquinoline-5,8-dione was prepared according to the following general procedures.The first step is the nitration of 8-Hydroxy-2-methylquinoline. 8-Hydroxy-2methylquinoline is reacted with 70% mixture of HNO3/H2SO4 to produce 5,7-dinitro-8hydroxy-2-methylquinoline. The next step requires hydrogenation and acylation. 5,7Dinitro-8-hydroxy-2-methylquinoline was reduced by H2/Pd-C in the presence of HCl and H20 filtered and then treated with sodium sulfite, sodium acetate and acetic anhydride to yield 5,7-diacetamido-8-acetoxy-2-methylquinoline. 5,7-Diacetamido-8-acetoxy-2methylquinoline was oxidized by potassium dichromate to produce 7-acetamido-2methylquinoline-5,8-dione. 7-Acetamido-2-methylquinoline-5,8-dione was chlorinated using hydrogen chloride gas in dry methanol producing 7-amino-6-chloro-2methylquinoline-5,8-dione. Treatment of 7-amino-6-chloro-2-methylquinoline-5,8-dione with selenium dioxide, under reflux in 1,4-dioxane produced 7-amino-6-chloro-2formylquinoline-5, 8-dione.All structures were confirmed by 'H NMR, IR, EIMS, and HRMS. / Department of Chemistry
153

Synthesis of tryptophan amides and lavendamycin analogs

Mirzaei, Hamid January 2001 (has links)
The synthesis of 7-N-acetyl-3'-demethyllavendamycin propyl ester (61 ), 7-N-butr-3'-demethyllavendamycin amide of N,N-dimethylethylenediamine (62), 7-N-acetyllavendamycin butyl amide (64), 7-N- acetyllavendamycin amide of ethanolamine (63) are described. Incorporation of the Pictet-Spengler condensation of 7acetamido-2-formylquinoline-5, 8-dione (32) or 7-butyramido-2-formylquinoline-5, 8dione (7) with tryptophan propyl ester (65), L-tryptophan amide of N, N dimethylethylenediamine (66), f3-methyltryptophan butyl amide (68), or methyltryptophan amide of ethanolamine (67) in xylene afforded four lavendamycin analogs.Aldehydes 32, 74 and 86 were prepared according to the following general procedure. Nitration of 8-hydroxy-2-methylquinoline (69) yielded 8-hydroxy-2-methyl - 5,7-dinitroquinoline (29). Compound 29 was then hydrogenated and acylated with acetic anhydride or butyric anhydride or 2-furoyl chloride followed by hydrolysis to yield 5,7diacetamido-8-hydroxy-2-methylquinoline (75) or 5,7- dibutyramido-8- hydroxy-2methylquinoline (73) or 5,7-difuroylamino-8-hydroxy-2- methylquinoline (84). Compounds 75 and 73 and 84 were oxidized by potassium dichromate to give the corresponding 5,8-diones 31 or 72 or 85. Treatment of 31 or 72 or 85 with selenium dioxide in refluxing 1,4-dioxane afforded compounds 32 and 74 and 86, respectively.Tryptophan propyl ester (65) was synthesized via a Fischer esterification of Ltryptophan with propyl alcohol saturated with hydrogen chloride. Compounds 66, 67, 68, 76, 77, 78, 79, and 80 were synthesized via the conversion of esters to amides with dimethylaluminum amides. Tryptophan methyl ester (23) and (3-methyltryptophan methylester (11) were treated with premixed trimethylaluminum and primary amines and refluxed to afford the desired tryptophan and (3-methyltryptophan amides.The structures of the novel compounds 61, 62, 63, 64, 66, 67, 68, 76, 77, 78, 79, 80, were confirmed through 1H NMR, IR, EIMS, and HRMS. Elemental analyses of Compounds 66, 68, 76, 77, 78 and 80 were also included. 1H NMR and IR for known compounds 29, 30, 31, 32, 71, 73, 74, 75, 84, 85, 86 were provided also. / Department of Chemistry
154

Chemistry of quinoline-2-carbaldehyde derivatives with malononitrile and formation of indolizines

Murali, Dheeptha 13 August 2011 (has links)
The quinoline-5,8-diones are an important class of compounds with a wide spectrum of biological activites such as antibacterial, antiasthmatic, antifungal, antitumour and antiparasitic agents. Over the past three decades many variously substituted derivatives of quinoline-5,8-diones have been synthesized and reported. The majority of them dealt with the chemistry of C-6 and/or C-7 substituted quinolinediones and were related to Lavendamycin. Our lab has developed several procedures for the condensation (Knoevenagel) and reduction of aldehydes and ketones with malononitrile. When this reductive alkylation procedure was attempted with quinoline-2-carboxaldehyde, a crude product was observed by NMR spectroscopy. This product rearranged upon attempted purification via recrystallization or column chromatography. The nucleophilic attack of the quinoline N on the C of the nitrile followed by a proton transfer and a tautomerization resulted in the creation of indolizine. We will study the reductive alkylation of a series of quinoline-5,8-diones with carboxaldehydes at the C-2 position with malononitrile. This reaction is carried out in 95% ethanol with no catalysts present. This reaction mixture is then diluted with additional 95% ethanol and then cooled in an ice/water bath before the addition of sodium borohydride (NaBH4) to afford the desired monosubstituted malononitrile. We have also carried out the reactions with a range of other substituted quinoline compounds. In these cases the indolizines were not observed. It is assumed that the indolizine product does not form due to the presence of substituents on the C-8 position. Additional studies will focus on unsubstituted C-8 quinoline rings to prepare other novel indolizines. Otherwise, various reactions are performed to force the formation of indolizine. / Introduction/background -- Preparation of quinoline derivatives and their respective carboxaldehydes -- Preparation of monosubstituted malononitriles and indolizines. / Department of Chemistry
155

ANSA bridged metallocene chemistry of niobium

Bailey, Nigel J. January 1998 (has links)
This thesis is concerned with the synthesis and characterisation of new ansa bridged bis-η-cyclopentadienyl derivatives of niobium. Chapter 1 provides an introduction to the area of early transition metal bent metallocene derivatives and charts the development of ansa bridged metallocenes. Chapter 2 presents the synthesis and characterisation of some new ansa niobocene derivatives prepared from niobium(IV) chloride. The compounds [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>- η-C<sub>5</sub>H<sub>4</sub>)(η<sup>2</sup>-BH<sub>4</sub>)],* [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η-C<sub>5</sub>H<sub>4</sub>)(PMe3)H],* [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η- C<sub>5</sub>H<sub>4</sub>)(PPh<sub>3</sub>)H], [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η-C<sub>5</sub>H<sub>4</sub>)(SPh)<sub>2</sub>] and [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η- C<sub>5</sub>H<sub>4</sub>)(CH2Ph)2]* are described. An asterisk indicates that the X-ray crystal structure was determined. Chapter 3 describes the synthesis and characterisation of some ansa niobocene derivatives containing ancillary imido ligands. The compounds [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η- C<sub>5</sub>H<sub>4</sub>)(NSiMe<sub>3</sub>)Cl],* [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η-C<sub>5</sub>H<sub>4</sub>)(NBu')X] (X = Cl,* Br,* I,* Me), [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η-C<sub>5</sub>H<sub>4</sub>)(NHBu')Cl][BF<sub>4</sub>)]and[Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η-C<sub>5</sub>H<sub>4</sub>)(O)Cl]* are described. An asterisk indicates that the X-ray crystal structure was determined. Photoelectron spectra were recorded for [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η-C<sub>5</sub>H<sub>4</sub>)(NBu')X] (X = Cl, Me) and compared to a geometry optimisation calculation obtained using density functional theory. In these formally twenty electron compounds the HOMO has negligible metal contribution and the eighteen electron rule is not violated. Chapter 4 describes the results of a preliminary investigation into ansa niobium(III) bis-η-cyclopentadienyl derivatives containing phosphorus donor ligands. The compound [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η-C<sub>5</sub>H<sub>4</sub>)(PMe<sub>3</sub>)Cl] is characterised spectroscopically. The synthesis and full characterisation details of the compound [Nb(η-C<sub>5</sub>H<sub>4</sub>-CMe<sub>2</sub>-η- C<sub>5</sub>H<sub>4</sub>){P(OMe)<sub>3</sub>}Cl] are given, including the X-ray crystal structure. Chapter 5 provides the experimental details for the preceding Chapters and Chapter 6 contains the characterising data for the new compounds described in this thesis. Full details of the X-ray crystallographic structure determinations are given in Appendices A -1.
156

Synthetic inorganic chemistry : novel metallocenes and inorganic fullerenes

Clancy, Gerald Patrick January 2000 (has links)
This thesis is divided into two parts. The first part concerns the synthesis and characterisation of substituted metallocene complexes of the transition and main group metals. The second part describes the preparation and characterisation of inorganic fullerene (IF)-related materials. <strong>Chapter 1</strong> reviews the chemistry of dialkyl- and diaryl-phosphino substituted cyclopentadienyl complexes of the transition metals. <strong>Chapter 2</strong> describes the synthesis and characterisation of the new ligands [M(C<sub>5</sub>Me<sub>4</sub>)CH<sub>2</sub>PMe<sub>2</sub>] (M = H, Li, Na and K) via the precursors [HC<sub>5</sub>Me<sub>4</sub>)CH<sub>2</sub>PHMe<sub>2</sub>][X] (X = Cl and PF<sub>6</sub>). The synthesis, characterisation and chemical reactivity of the compounds [Zr{{η-C<sub>5</sub>Me<sub>4</sub>)CH<sub>2</sub>PMe<sub>2</sub>}<sub>2</sub>Cl<sub>2</sub> and [Mn{η-C<sub>5</sub>Me<sub>4</sub>)CH<sub>2</sub>PMe<sub>2</sub>}<sub>2</sub>] is reported together with supporting evidence for the synthesis of the bimetallic complex [Zr{U+03B7-C<sub>5</sub>Me<sub>4</sub>)CH<sub>2</sub>PMe<sub>2</sub>}<sub>2</sub>Cl<sub>2</sub>PtI<sub>2</sub>] and the complex [Mn{η-C<sub>5</sub>Me<sub>4</sub>)CH<sub>2</sub>PMe<sub>2</sub>B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>}<sub>2</sub>]. <strong>Chapter 3</strong> provides a brief introduction into the field of main group metallocenes and describes the synthesis and characterisation of the new main group metallocenes [M{η- C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>PMe<sub>2</sub>}<sub>2</sub>] (M = Pb and Sn). The B(C<sub>6</sub>F<sub>5</sub>)<sub>3 adduct [Pb{η-C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>PMe<sub>2</sub>(B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>}<sub>2</sub>] has also been synthesised. The main group - transition metal bimetallic complex [Pb{η-C<sub>5</sub>H<sub>4</sub>)CMe<sub>2</sub>PMe<sub>2</sub>}<sub>2</sub>PtI<sub>2<sub> in which the substitutedplumbocene acts as a bidentate ligand, has been characterised by mass spectrometry and <sup>31</sup>P{<sup>1</sup>H}NMR spectroscopy. <strong>Chapter 4</strong> provides an introduction into the field of IF-related materials and an overview of the analytical techniques used in their characterisation. <strong>Chapter 5</strong> describes the preparation and characterisation of IF-MoS<sub>2</sub> and IF-(Nb,W)S<sub>2</sub> materials from MoC and the binary oxides Nb<sub>8</sub> W<sub>9</sub>O<sub>47</sub> and Nb<sub>4</sub>W<sub>13</sub>O<sub>47</sub> respectively. A powder X-ray diffraction study of the conversion of WC to WO<sub>3-X</sub> and the subsequent sulfidisation by H<sub>2</sub>S to form novel IF-WS<sub>2</sub> morphologies is also described. <strong>Chapter 6</strong> describes the preparation of amorphous Group 5 metal (V, Nb and Ta) oxides using the metal vapour synthesis technique. These amorphous precursors have been annealed in a reducing atmosphere to form the oxide phases U+03B1-V<sub>2</sub>O<sub>3</sub>, NbO<sub>2</sub> and TT-Ta<sub>2</sub>O<sub>5</sub> which have been identified by powder X-ray diffraction. Upon reaction with H<sub>2</sub>S, the crystalline oxides afford layered sulfides of the form MS<sub>2</sub> (M = V, Nb and Ta), some of which exhibit behaviour typical of IF-like materials and have been characterised by HRTEM, powder X-ray diffraction and EDX analysis. Chapter 7 outlines the experimental details for the synthesis, characterisation, reactions and compounds described in the preceding chapters. <strong>Chapter 8</strong> presents the characterising data for the new compounds described in chapters 2 and 3. <strong>Appendix A</strong> contains details of the crystallographic data for the structurally characterised compound [Mn{η-C<sub>5</sub>Me<sub>4</sub>)CH<sub>PMe<sub>2</sub>}<sub>2</sub>].
157

Amino sugars and their glycosides

Hindle, Neil January 1995 (has links)
This thesis describes approaches to the transformation of simple carbohydrates into a polyhydroxylated pyrrolidine and the formation of its glucosides. Chapter one describes the synthesis of the naturally occurring pyrrolidine 2,5-dideoxy-2,5-imino-D-mannitol. Synthesised from di-O-isopropylidene-D-glucose, the key steps are the introduction of nitrogen at C-5 with retention of configuration. Then cyclisation of the nitrogen onto the C-2 position with inversion to form the pyrrolidine ring. Reduction of the aldehyde furnished the polyhydroxylated heterocycle in 3.4% yield over 16 steps. The synthetic compound matched the naturally occurring compound in all respects. Chapter two contains a review of commonly used glycosylation methods. It also describes the glycosylation of di-O-isopropylidene-α-D-glucose as a model system comparing the Koenig-Knorr method to the trichloroacetimidate method using several reaction conditions. Glycosylation of 2,5-dideoxy-2,5-imino-D-mannitol was carried out using the trichloroacetimidate method to synthese all four glucosides. Boron trifluoride etherate and trimethylsilyl trifluoromethanesulphonate were used as catalysts in dichloromethane, diethyl ether and acetonitrile under strictly anhydrous conditions. All four glucosides were prepared 1-O-(αβ-D-glucopyranosyl)-2,5-dideoxy-2,5-imino-D-mannitol and 3-O-(αβ-D-glucopyranosyl)-2,5-dideoxy-2,5-imino-D-mannitol. Biological screening carried out against a wide range of glycosidases and glycosyl transferases indicated that the glucosides showed little inhibition in comparison to 2,5-dideoxy-2,5-imino-D-mannitol. Chapter three describes the isolation and identification of 1-O-(β-D-glucopyranosyl)- 2,5-dideoxy-2,5-imino-D-mannitol from Nephthytis poisonii N.E.Br. a member of the Araceae family found in tropical Africa. Identification was made by comparison with the previously synthesised glucosides of 2,5-dideoxy-2,5-imino-Dmannitol. Investigations of Hyacinthoides non-scriptus (L.) chouard ex Rothm are also discussed. Chapter four describes the synthesis of a diazidolactone that could be used to form a 1,5 disubstituted tetrazole. This would have a second nitrogen functionality in the molecule allowing the possibility of the inclusion of the tetrazole into a peptide sequence. The synthesis was carried out from L-gulono-1,4-lactone. An azido group was introduced selectively at C-2, this unexpectedly occurred with retention of configuration. A second azide was then introduced at C-5, this occurring with the more commonly observed inversion of configuration to afford the 2,5-diazido-2,5-dideoxy-D-manno-1,4-lactone.
158

Empirical essays on financial economics /

Degrér, Henrik January 2004 (has links)
Diss. Lund : Univ., 2004.
159

A survey of the various commercial chlorine products available and the practical applications in in the problems of sanitation a thesis submitted in partial fulfillment ... Master of Science in Public Health ... /

Sakai, Peter H. January 1940 (has links)
Thesis (M.S.P.H.)--University of Michigan, 1940.
160

A survey of the various commercial chlorine products available and the practical applications in in the problems of sanitation a thesis submitted in partial fulfillment ... Master of Science in Public Health ... /

Sakai, Peter H. January 1940 (has links)
Thesis (M.S.P.H.)--University of Michigan, 1940.

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