Results 321 to 330 of about 176,899 (357)

Aromaticity in Heterocyclic Compounds

2009
M. Agostinha, R. Matos, J.F.Liebman: Experimental Thermochemistry of Heterocycles and Their Aromaticity: A Study of Nitrogen, Oxygen and Sulfur Derivatives of Indane and Indene.- L. Nyulaszi, Z. Benko: Aromatic Phosphorus Heterocycles.- M. Stepien, L. Latos-Grazynski: Aromaticity and Tautomerism in Porphyrins and Porphyrinoids.- I. Alkorta, J. Elguero:
Tadeusz M. Krygowski, Michał K. Cyrański   +1 more
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Heterocyclic compounds—II

Tetrahedron, 1970
Abstract In the presence of alkali bases, o-hydroxyphenyl-γ-chloroamide (I) produces pyrrolidin-2-one (II) by an N−-5 cyclization, while other ω-chloroamides (I, n = 1,2) only undergo O−-ring closures. The results emphasize the importance of the size of the resulting rings on the course of the cyclization of o-hydroxyphenyl-ω-haloamides (I, n = 1,2,3)
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Heterocycle Compounds with Antimicrobial Activity

Current Pharmaceutical Design, 2020
Background:Bacterial infections are a growing problem worldwide causing morbidity and mortality mainly in developing countries. Moreover, the increased number of microorganisms, developing multiple resistances to known drugs, due to abuse of antibiotics, is another serious problem.
Maria Fesatidou, Anthi Petrou, Geronikaki Athina   +2 more
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Organoboron heterocyclic compounds

Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1959
1. The reactions of organomagnesium compounds of furan and 2-methylfuran with potassium fluoborate were investigated. 2. For the first time, heterocyclic trisubstituted organoboron compounds were prepared (derivatives of 2-methylfuran, thiophene, and selenophene).
A. N. Nesmeyanov, V. N. Drozd, V. A. Sazonova   +2 more
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Formation of Heterocyclic Compounds

1984
Whereas the formation of carbon—carbon bonds using transition metal intermediates has been relatively well studied, the synthesis of heterocyclic compounds using transition metals has attracted much less attention. Indeed in recent years only two reviews on the subject have appeared.1 As the demand for new heterocyclic compounds increases, particularly
M. V. Twigg, H. M. Colquhoun, J. Holton, D. J. Thompson   +3 more
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The Quaternization of Heterocyclic Compounds

1964
Publisher Summary This chapter discusses the quaternization of heterocyclic compounds. The reagents for quaternization including—alkyl halides and related compounds, aryl and heterocyclyl halides, solvents, and various other quaternizing reagents—have also been discussed.
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Cancer Chemotherapy and Heterocyclic Compounds

Current Medicinal Chemistry, 2002
The search for pharmacological approaches to neoplastic disease has made some impressive gains started after 1940 when the antileukemic activity of nitrogen mustard was discovered during world war II. It is generally accepted that neoplastic transformation is related to genes alteration or oncogene activation, so the progress in the development of the ...
R. Mohan, R. Venktaramanan, P. Sapra, Mazaahir Kidwai   +3 more
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Monocyclic Heterocyclic Compounds

1967
The polarographic reduction of a group in the side chain of a heterocyclic ring usually follows a path analogous to that followed by the corresponding benzene compound. Most deviations from this rule have been observed in the pyridine series (e.g., for aldehydes, 1–9 acids,10–12 nitriles,13 and acetyl derivatives9,14) In these compounds hydrogenation ...
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Fluorinated heterocyclic compounds

Dyes and Pigments, 1982
Abstract Fluorinated heterocyclic compounds have many features which distinguish them from other corresponding halogenated compounds. The reasons for the distinctive properties of fluorine are reviewed in relation to nucleophilic substitution reactions.
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Cyanoacetohydrazides in Synthesis of Heterocyclic Compounds

Topics in Current Chemistry, 2018
Use of cyanoacetohydrazides as precursors in reactions leading to construction of heterocycles is reviewed. In addition to some common heterocyclic compounds, synthesis of other uncommon heterocycles such as thiadiazole, oxadiazole, fused heterocycles, and some seven- and eight-membered heterocycles such as benzodiazepine, oxazepine, and benzoxocine ...
Hajar Hosseini, Mohammad Bayat
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