Results 171 to 180 of about 8,136 (224)

Pyridine-2-thiones, 2-pyrone phenylhydrazones, and 2-pyridones from 2-pyrones

Journal of the Chemical Society C: Organic, 1971
Various 5-aryloxypyran-2-thiones, 2-pyridones, and 1-amino-2-pyridones have been prepared. The pyran-2-thiones were converted into pyridine-2-thiones and phenylhydrazones. Some derivatives of 6-p-bromophenyl-5-phenoxy-4-phenyl-2-pyrone (Ia) are described.
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A Concise Access to 3-Substituted 2-Pyrones.

The Journal of Organic Chemistry, 2010
The development of a modular synthesis of 3-substituted-2-pyrones is described. The attainment of this strategy hinges on a new electrophilic pyrone derivative which can be readily prepared on a multigram scale and which performs very competently in metal-catalyzed cross-coupling reactions with a variety of nucleophiles.
Frébault, F., Oliveira, M., Wöstefeld, E., Maulide, N.   +3 more
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One step preparation of bromo-2-pyrones via bromo-decarboxylation of 2-pyrone-carboxylic acids

Tetrahedron Letters, 2001
Abstract Synthetically valuable 3-bromo-2-pyrone, 3-bromocoumarin, 5-bromo-2-pyrone, and 3,5-dibromo-2-pyrone were prepared in one step from readily available 2-pyrone-carboxylic acids via bromo-decarboxylation in good to fair yields.
Cheon-Gyu Cho, Jung-Sang Park, In-Hak Jung, Haiwon Lee   +3 more
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Substituted 2‐Pyrones and 5,6‐Dihydropyrones

Journal of Heterocyclic Chemistry, 1985
AbstractA series of substituted 2‐pyrones and 5,6‐dihydropyrones have been synthesized and investigated for their inhibitory activity toward human leukocyte elastase, procine pancreatic elastase and chymotrypsin.
William C. Groutas, Tien L. Huang, Michael A. Stanga, Michael J. Brubaker, Min K. Moi   +4 more
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Phenolic derivatives of 2-pyrone. I.

Chemistry of Heterocyclic Compounds, 1971
The condensation of hydroxy- and methoxyacetophenones with 1,1,1,3-tetrachloro-3-ethoxypropane or β, β-dichloroacrolein in an acid medium has yielded a number of dichlorodienyl hydroxyphenyl ketones which are converted into the corresponding 2-pyrones in acetic or propionic acids in the presence of phosphoric acid.
Yu. V. Maevskii, S. V. Sokolovskaya, I. P. Komkov   +2 more
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On the nitration of 2‐pyrone

Journal of Heterocyclic Chemistry, 1969
AbstractA 1:1 adducl of 2‐pyrone and nitronium fluoroborate has been delected by nmr and is a possible precursor of 5‐nitro‐2‐pyrone, a subsequently formed product. From comparison of the nmr spectra of the 1:1 adduct and 2‐methoxypyrylium fluoroborate, the adduct is believed to be the pyrylium fluoroborate derived from nitration of the carbonyl oxygen
W. H. Pirkle, M. Dines
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3-Hydroxy-2-pyrone

2001
[496-64-0] C5H4O3 (MW 112.09) InChI = 1S/C5H4O3/c6-4-2-1-3-8-5(4)7/h1-3,6H InChIKey = LIPRKYKMVQPYPG-UHFFFAOYSA-N ([4 + 2] cycloaddition vinylketene diene equivalent2, 3) Physical Data: white, crystalline solid; mp 92 °C; mp (dihydrate) 80–85 °C; bp 112 °C/20 mmHg; sublimes at 50 °C/4 mmHg; λmax 294 nm (H2O ...
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Iodination of 6-aryl-2-pyrones

Chemistry of Heterocyclic Compounds, 1984
The iodination of 6-aryl-2-pyrones with iodine chloride in glacial acetic acid leads to the corresponding 3-iodo derivatives. 3-Cyano-6-phenyl-2-pyrone and 3-phenylethynyl-6-phenyl-2-pyrone were obtained by replacement of the iodo group by cyano and phenylethynyl groups.
S. V. Sokolovskaya, L. K. Moldovanova
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Asymmetric Hydrogenation of Substituted 2-Pyrones

The Journal of Organic Chemistry, 1999
Various substituted 2-pyrones have been hydrogenated with high enantioselectivity (up to 97% ee) to the corresponding 5,6-dihydropyrones using cationic ruthenium catalysts containing the (6,6‘-dimethoxybiphenyl-2,2‘diyl)bis[3,5-di(tert-butyl)phenylphosphine] ligand. When substituents at position 3 are absent, 5,6-dihydropyrones are further hydrogenated
Matthias J. Fehr, Giambattista Consiglio, Michelangelo Scalone, Rudolf Schmid   +3 more
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Synthesis of 5,6-Dihydro-2-pyrone and 2-Pyrone

Synthesis, 1974
Masako NAKAGAWA, Masakatsu TONOZUKA, Michiko OBI, Midori KIUCHI, Tohru HINO, Yoshio BAN   +5 more
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