scholarly journals The Acid-catalyzed Bromination of Aromatic Compounds with Potassium Bromate in Aqueous Acetic Acid

1968 ◽  
Vol 41 (4) ◽  
pp. 997-1000 ◽  
Author(s):  
Yoshiaki Furuya ◽  
Atsushi Morita ◽  
Iwao Urasaki
Keyword(s):  
Acetic Acid ◽  
Aromatic Compounds ◽  
Potassium Bromate ◽  
Aqueous Acetic Acid ◽  
Acid Catalyzed

Oxidation of α-Hydroxy Acids with Quinolinium Dichromate - A Kinetic Study

1993 ◽  
Vol 58 (7) ◽  
pp. 1624-1630 ◽  
Author(s):  
Kailasa Aruna ◽  
Prerepa Manikyamba ◽  
Embar Venkatachari Sundaram
Keyword(s):  
Dielectric Constant ◽  
Acetic Acid ◽  
Bond Cleavage ◽  
Low Dielectric Constant ◽  
Aqueous Acetic Acid ◽  
Hydroxy Acids ◽  
First Order ◽  
Low Dielectric ◽  
Chloro Derivative ◽  
Acid Catalyzed

Oxidation of lactic acid, α-hydroxyphenyllacetic acid and its 4-chloro derivative with quinolinium dichromate (QDC) in 30% (v/v) aqueous acetic acid at 303 K are first order in QDC and first-order in hydroxy acids. The reactions are acid-catalyzed and a medium of low dielectric constant favours the oxidation. The products are the corresponding aldehydes. Thermodynamic parameters are evaluated and a mechanism involving a C-C bond cleavage is proposed.

Acid-catalyzed migration of N4-acyl groups in cytosine derivatives

1979 ◽  
Vol 44 (6) ◽  
pp. 1819-1827 ◽  
Author(s):  
Antonín Holý
Keyword(s):  
Acetic Acid ◽  
Trifluoroacetic Acid ◽  
The Other ◽  
Aqueous Acetic Acid ◽  
Amino Group ◽  
Benzoyl Group ◽  
Benzoyl Cyanide ◽  
Acid Catalyzed ◽  
Derivatives Of ◽  
Anhydrous Acetic Acid

Heating 1-(2,3-di-O-benzoyl-β-D-arabinofuranosyl)-N4-benzoylcytosine (I) in 80% acetic acid afforded 1-(2,3-di-O-benzoyl-β-D-arabinofuranosyl)-N3-benzoylcytosine (II). Benzoylation of 5'-O-tritylcytidine (V) led to the 2',3',N4-tribenzoyl derivative VI which was refluxed with 80% acetic acid to give 2',3',N3-tribenzoylcytidine (VII). Analogously, 2',3',5',N4-tetrabenzoylcytidine (IX), prepared by benzoylation of cytidine with benzoyl cyanide, gave on reflux with 80% acetic acid 2',3',5',N3-tetrabenzoylcytidine (X). Under identical conditions, 1-methyl-N4-benzoylcytosine (XI) afforded directly 1-methyluracil (XII) .This migration takes place also in acetyl derivatives of cytosine nucleosides: 2',3',5',N4-tetraacetylcytidine (XIII) was transformed to the N3-acetylcytosine derivative XIV. On the other hand, migration of acetyl or benzoyl group from the exo-amino group of adenine has not been observed under the mentioned conditions. The migration of the N4-acyl group of cytosine derivatives proceeds best in aqueous acetic acid, more slowly also in anhydrous acetic acid, but not by action of trifluoroacetic acid in 1,2-dichloroethane.

Isocarbostyrils. I. Electrophilic Substitution Reactions

1971 ◽  
Vol 49 (17) ◽  
pp. 2785-2796 ◽  
Author(s):  
D. E. Horning ◽  
G. Lacasse ◽  
J. M. Muchowski
Keyword(s):  
Acetic Acid ◽  
Melting Point ◽  
Electrophilic Substitution ◽  
Aqueous Acetic Acid ◽  
Substitution Reactions ◽  
Normal Product ◽  
Mild Conditions ◽  
Acid Catalyzed ◽  
Considerable Detail ◽  
Sole Product

The electrophilic substitution of N-alkylated isocarbostyrils was examined in considerable detail. Bromination, acylation, nitration, and acid-catalyzed condensation with formaldehyde occurred exclusively at C-4 under relatively mild conditions. The acylation of isocarbostyrils has heretofore not been reported.The bromination of 2-methyl-5-nitroisocarbostyril in aqueous acetic acid gave 2-methyl-3,4-dihydro-3-hydroxy-4-bromo-5-nitroisocarbostyril (7) of unknown stereochemistry, as the sole product. When heated above its melting point, 7 lost the elements of water to give the "normal" product of bromination 8.In aqueous acetic acid, excess bromine was shown to convert isocarbostyrils to the corresponding 3,4-dihydro-3-hydroxy-4,4-dibromo derivatives whose structures were supported by spectral and degradative evidence.

Novel Compound from Flowers of Moringa oleifera Active Against Multi- Drug Resistant Gram-negative Bacilli

2020 ◽  
Vol 20 (1) ◽  
pp. 69-75
Author(s):  
Santi M. Mandal ◽  
Subhanil Chakraborty ◽  
Santanu Sahoo ◽  
Smritikona Pyne ◽  
Samaresh Ghosh ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Moringa Oleifera ◽  
Aqueous Acetic Acid ◽  
Phytochemical Analysis ◽  
Hydroxyl Groups ◽  
Drug Resistant ◽  
Gram Negative ◽  
Isolated Compound ◽  
Conventional Antibiotics

Background: The need for suitable antibacterial agents effective against Multi-drug resistant Gram-negative bacteria is acknowledged globally. The present study was designed to evaluate the possible antibacterial potential of an extracted compound from edible flowers of Moringa oleifera. Methods: Five different solvents were used for preparing dried flower extracts. The most effective extract was subjected to fractionation and further isolation of the active compound with the highest antibacterial effect was obtained using TLC, Column Chromatography and reverse phase- HPLC. Approaches were made for characterization of the isolated compound using FTIR, NMR and Mass spectrometry. Antibacterial activity was evaluated according to the CLSI guidelines. Results: One fraction of aqueous acetic acid extract of M. oleifera flower was found highly effective and more potent than conventional antibiotics of different classes against Multi-drug resistant Gram-negative bacilli (MDR-GNB) when compared. The phytochemical analysis of the isolated compound revealed the presence of hydrogen-bonded amine and hydroxyl groups attributable to unsaturated amides. Conclusion: The present study provided data indicating a potential for use of the flowers extract of M. oleifera in the fight against infections caused by lethal MDR-GNB. Recommendations: Aqueous acetic acid flower extract of M. oleifera is effective, in-vitro, against Gram-negative bacilli. This finding may open a scope in pharmaceutics for the development of new classes of antibiotics.

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