Substituent effects of phosphorus and arsenic containing groups in aromatic substitution. VI. Orientation in nitration of some anilides and phenyl esters

1976 ◽  
Vol 54 (4) ◽  
pp. 560-565 ◽  
Author(s):  
Tomasz A. Modro ◽  
Jerzy Pioch
Keyword(s):  
Acetic Anhydride ◽  
Substituent Effects ◽  
Aromatic Substitution ◽  
Phosphorylated Compounds ◽  
Derivatives Of ◽  
Acyl Derivatives ◽  
Meta Isomer

The orientation in nitration of N-acyl derivatives of aniline and O-acyl derivatives of phenol in aqueous H2SO4 and in acetic anhydride has been studied. Acetyl and methanesulfonyl derivatives are exclusively ortho/para directing, whereas the N- and O-phosphorylated compounds yield in both media considerable amounts of the meta isomer. The observed differences in orientation are discussed in terms of different protonation sites and strong πp−πd interactions of the oxygen or nitrogen and the P(IV) atom.

Thiohydantoins. II. Thiohydantoins Derived from Aspartic and Glutamic Acids

1952 ◽  
Vol 5 (4) ◽  
pp. 721
Author(s):  
JM Swan
Keyword(s):  
Acetic Anhydride ◽  
Carboxylic Acids ◽  
Ammonium Thiocyanate ◽  
Derivatives Of ◽  
Isomeric Pairs ◽  
Acyl Derivatives

N-Acyl derivatives of the &carboxylic acids, aspartic and glutamic acids, yield the corresponding anhydrides when heated with acetic anhydride in the presence or absence of ammonium thiocyanate. In general these anhydrides form isomeric pairs of amides and anilides, and only one of each pair can be converted into the corresponding 2-thiohydantoin. The anhydrides from N-phenylacetyl- and N-p-nitro-benzoylglutamic acids, and N-acetylaspartic acid have been regarded hitherto as oxazolones.

Infrared spectra and substituent effects in 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones

1983 ◽  
Vol 48 (2) ◽  
pp. 586-595 ◽  
Author(s):  
Alexander Perjéssy ◽  
Pavol Hrnčiar ◽  
Ján Šraga
Keyword(s):  
Substituent Effects ◽  
Phenyl Group ◽  
Wave Number ◽  
Vibrational Coupling ◽  
Wave Numbers ◽  
Stretching Vibration ◽  
Stretching Vibrations ◽  
The Relationship ◽  
Derivatives Of ◽  
Effect Of Structure

The wave numbers of the fundamental C=O and C=C stretching vibrations, as well as that of the first overtone of C=O stretching vibration of 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones and 1,3-cycloheptanedione were measured in tetrachloromethane and chloroform. The spectral data were correlated with σ+ constants of substituents attached to phenyl group and with wave number shifts of the C=O stretching vibration of substituted acetophenones. The slope of the linear dependence ν vs ν+ of the C=C stretching vibration of the ethylenic group was found to be more than two times higher than that of the analogous correlation of the C=O stretching vibration. Positive values of anharmonicity for asymmetric C=O stretching vibration can be considered as an evidence of the vibrational coupling in a cyclic 1,3-dicarbonyl system similarly, as with derivatives of 1,3-indanedione. The relationship between the wave numbers of the symmetric and asymmetric C=O stretching vibrations indicates that the effect of structure upon both vibrations is symmetric. The vibrational coupling in 1,3-cycloheptanediones and the application of Seth-Paul-Van-Duyse equation is discussed in relation to analogous results obtained for other cyclic 1,3-dicarbonyl compounds.

scholarly journals Synthesis, Antiproliferative Activity and Radical Scavenging Ability of 5-O-Acyl Derivatives of Quercetin

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1608
Author(s):  
Stephen Lo ◽  
Euphemia Leung ◽  
Bruno Fedrizzi ◽  
David Barker
Keyword(s):  
Antiproliferative Activity ◽  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Breast Cancer Cell Lines ◽  
Scavenging Activity ◽  
Plant Materials ◽  
Wide Range ◽  
Derivatives Of ◽  
Acyl Derivatives

Quercetin is a flavonoid that is found in many plant materials, including commonly eaten fruits and vegetables. The compound is well known for its wide range of biological activities. In this study, 5-O-acyl derivatives of quercetin were synthesised and assessed for their antiproliferative activity against the HCT116 colon cancer and MDA-MB-231 breast cancer cell lines; and their radical scavenging activity against the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical species. Four derivatives were found to have improved the antiproliferative activity compared to quercetin whilst retaining radical scavenging activity.

ChemInform Abstract: O-ACYL DERIVATIVES OF 2-PYRIDINALDOXIME

1978 ◽  
Vol 9 (52) ◽  
Author(s):  
P. YA. ROMANOVSKII ◽  
A. YU. KRIKIS ◽  
G. I. CHIPENS
Keyword(s):  
Derivatives Of ◽  
Acyl Derivatives
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