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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 91 for “"Aromatic Ring"”.
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Studies on the Biosynthesis of the Aromatic Ring of Chloramphenicol
Made available in DSpace on 2014-12-09T17:35:28Z (GMT). No. of bitstreams: 1 6607782.pdf: 6734664 bytes, checksum: 76a363f3bb9946fc409884deeb832f57 (MD5) Previous issue date: 1966
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Spectroscopic and electrochemical investigation of phenyl, phenoxy, and hydroxyphenyl-terminated alkanethiol monolayers
… voltametry, and impedance spectroscopy. Several aromatic C-C vibrational frequencies in the RAIRS spectra, for SAMs of 1-8, reveal a dependence of peak intensity on substitution regiochemistry of the aromatic ring. This result suggests that the orientation of the aromatic ring changes with …
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Quantitative Analysis of Acetylsalicylic Acid by q-NMR (Quantitative-Nuclear Magnetic Resonance Spectroscopy)
<p>Quantitative analysis is an important step during pharmaceutical drug development. Currently, the pharmaceutical industry uses high performance liquid chromatography (HPLC) for quantitative analysis of organic compounds as the preferred technique. The proton nuclear magnetic resonance (NMR) …
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New Methods in Aryne Chemistry
… polyaryl compounds. They are neutral, reactive, aromatic intermediates lacking two adjacent hydrogen atoms on an aromatic ring. They offer the strategic advantage of rapidly functionalizing an aromatic ring by forming multiple carbon−carbon or carbon−heteroatom bonds in a single operation, often …
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Regiospecific Synthesis of Ortho Substituted Phenols
<p>Phenol is highly reactive toward electrophilic aromatic substitution. By this general approach, many groups can be appended to the ring, via halogenation, acylation, sulfonation, and other processes. Phenol contains the hydroxyl group (–OH), which is a strongly activating ortho/para directing …
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Studies directed toward the total synthesis of salvilenone
… an alkoxy acetylene moiety which assembles an aromatic ring in one step from acyclic precursors followed by an intramolecular [4 + 2] cycloaddition of a conjugated enyne and benzyne intermediate.
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Avaliação da atividade antifúngica de ésteres benzoicos estruturalmente relacionados frente a espécies de Candida
… and position of the various substituents of the aromatic ring of the esters, including: -OH, -CH3, -Ar, NO2, in the biological activity. The results were satisfactory. The bioactive substances showed good to moderate the bioactivity; the best MIC vary between 256μg / ml and 64μg / ml, this last …
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Nitrophenyl boronic acids as derivatizing agents in chromatography
… most important stability factor is the boronate ring size, this is followed by the alkyl substitution present and the position of the nitro group on the aromatic ring. Excellent quantitative performance was obtained with flame ionization and electron capture detectors. Detection limits in the …
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Routes to drimanes from podocarpic acid
… (9) has been investigated. Modification of the aromatic ring of (9) has given 11- and l4-hydroxypodocarpatrienes which were ozonised to give the congeners (31), (34), and (36) of the naturally occurring drimanes confertifolin (6), isodrimenin (7), and winterin (8). The oxidation of a …
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CH-[pi] interactions play a central role in protein recognition of carbohydrates/
… of a carbohydrate and the [pi] system of an aromatic ring. In this thesis, I examine the fundamental nature, strength, and biological significance of this interaction, largely in the context of a family of carbohydrate-binding proteins known as galectins. In Chapter 1, I review previous …
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Combining chemical with biological oxidation for efficient treatment of chloronitrobenzene in groundwater
Chloronitrobenzene (CNB) is a chloronitroaromatic compound widely used in the synthetic production of pharmaceuticals, pesticides, dyes, lumber preservatives, and many other industrial products. CNB has been recognized as a toxic organic contaminant to humans and is recalcitrant to microbial …
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Synthesis and characterization of Pentaaquo-4-pyridylchromium (III) ion
… +1 charge would be distributed throughout the aromatic ring of the resulting pyridinium ion, thus increasing all charges. Benzene would show all carbons being identical having relative charges of zero each on the scale used for pyridine. As a result of these considerations, an attempt at the …
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PART I PREPARATION OF NOVEL LACTONES AND THEIR PRECURSORS DERIVED FROM METHYL SALICYLATE PART II NUCLEOPHILIC AROMATIC SUBSTITUTION IN A DINITROSALICYLIC LACTONE WITH RING OPENING AND ELIMINATION VIA MEISENHEIMER INTERMEDIATES
… described. The influence of substituents on the aromatic nucleus in affecting ring closure reactions was examined. Experimental results show that ring closure is enhanced when nitro groups are incorporated in the aromatic ring. Investigations were conducted in the preparation of compounds …
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Stereospecific Syntheses from Podocarpic Acid
… derivatives of diterpenoids possessing an aromatic ring-C is discussed and the assignment of configuration of the 6-bromo substituents from n.m.r. and n.0.e. data is examined. A preliminary investigation into the possibility of preparing a 9a-methyl steroidal analogue by addition of a …
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I. Synthesis of Myocardial Imaging Agents for Diagnosis of MCAD Deficiency. II. Synthesis of [fluorine-18] Fluoroaryl Estrogens as Receptor Based Tumor Imaging Agents for Breast Cancer
… of ($\sp{18}$F) F$\sp-$onto an electron-rich aromatic ring, but none have found general application. Several strategies were explored for the synthesis of a (fluorine-18) fluoroaryl estrogen. The synthesis of 2- ($\sp{18}$F) fluoroestradiol (12) required the use of a trimethylammonium salt as …
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Development of Novel Subtype Selective Ligands for the Estrogen Receptor: I. 5,6-Diakyl-5,6,11,12-Tetrahydrochrysenes as Estrogen Receptor-Beta Selective Antagonists. II. Diarylpropionitriles as Estrogen Receptor-Beta Potency Selective Agonists
… prepared where the both the ligand core and the aromatic rings were modified by the repositioning of phenolic hydroxy groups and by the addition of alkyl substituents and nitrile groups. Another series of DPN analogs were synthesized where the nitrile functionality was replaced with acetylene …
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Design and Synthesis of Thiamine Pyrophosphate (TPP) Analogues for Investigating the Structure-Activity Relationship (SAR) of Inhibitors of TPP-dependent Enzymes
… analogues, which typically feature a neutral aromatic ring in place of TPP’s positive thiazolium ring. In response to the growing demand in understanding the roles of TPP-dependent enzymes and their pathways within biological systems, development of membrane-permeable thiamine analogues is …
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Biodegradation of pesticide and indolic compounds under methanogenic conditions
… Net methane production suggested that the aromatic ring was not degraded. Rates of dicamba degradation were enhanced with addition of 0.2 % yeast extract. Dicamba degradation was accomplished within 4 days compared to 22 days without yeast extract addition. The inability of the consortium …
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On Metal synthesis of Some Substituted Rhenium and Manganese Complexes
… environmental stability as compared to their non-aromatic analogs (i.e. polyacetylene). Our current interest focus upon the potential role of metal ligand bound pyridazines as the next generation of electronic devices that utilize the metal ligands bound to organics as the semiconducting material. …
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The Chemistry of Cyclopropylarene Radical Cations
… if a radical cation is produced, it will undergo ring opening. Through a detailed examination of follow-up chemistry of electrochemically and chemically generated cyclopropylarene radical cations, we have shown that the assumption made in the use of these substrates as SET probes is not …
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