THE TRANSMISSION OF POLAR EFFECTS: IV. THE KINETICS OF ESTERIFICATION WITH DIAZODIPHENYLMETHANE OF SUBSTITUTED HETEROCYCLIC CARBOXYLIC ACIDS

1966 ◽  
Vol 44 (13) ◽  
pp. 1493-1499 ◽  
Author(s):  
Keith Bowden ◽  
D. C. Parkin
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Rate Coefficients ◽  
Relative Ability ◽  
Indole Carboxylic Acid ◽  
Kinetics Of ◽  
Electron Effects

The rate coefficients for the reaction with diazodiphenylmethane, in ethanol at 30.0°, of a number of substituted indole-2-carboxylic acids, indole-3-carboxylic acids, coumarin-3-carboxylic acids, coumarilic acids, and N-phenylglycines have been determined. The effect of substitution is assessed by use of adapted Hammett and Dewar–Grisdale relations. The relations give good correlations for oxygen-ring heterocyclic systems, and the relative ability of the systems to transmit π-electron effects has been determined. An anomalous perturbing effect appears to operate in the indole-carboxylic acid systems.

Synthesis of 3-(Cyclohexylamino)-2-arylimidazo[1,2-a]pyridine-8- carboxylic Acids Via an Efficient Three-component Condensation Reaction between Cyclohexylisocyanide and 2-Aminopyridine-3-carboxylic Acid in the Presence of Aromatic Aldehyde

2018 ◽  
Vol 21 (4) ◽  
pp. 298-301 ◽  
Author(s):  
Ghasem Marandi
Keyword(s):  
Biological Sciences ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
High Performance ◽  
Condensation Reaction ◽  
Aromatic Aldehydes ◽  
New Materials ◽  
One Pot ◽  
High Yields ◽  
Benzaldehyde Derivatives

Aim and Objective: The reaction of cyclohexylisocyanide and 2-aminopyridine-3- carboxylic acid in the presence of benzaldehyde derivatives in ethanol led to 3-(cyclohexylamino)-2- arylimidazo[1,2-a]pyridine-8-carboxylic acids in high yields. In a three component condensation reaction, isocyanide reacts with 2-aminopyridine-3-carboxylic acid and aromatic aldehydes without any prior activation. Material and Methods: The synthesized products have stable structures which have been characterized by IR, 1H, 13C and Mass spectroscopy as well as CHN-O analysis. Results: In continuation of our attempts to develop simple one-pot routes for the synthesis of 3- (cyclohexylamino)-2-arylimidazo[1,2-a]pyridine-8-carboxylic acids, aromatic aldehydes with divers substituted show a high performance. Conclusion: In conclusion, this study introduces the art of combinatorial chemistry using a simple one-pot procedure for the synthesis of new materials which are interesting compounds in medicinal and biological sciences.

Kinetics of Substitution of 4-Methoxyphenylazo Groups of 2,6-Dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic Acid by Reaction with 4-Nitrobenzenediazonium Cation

1994 ◽  
Vol 59 (7) ◽  
pp. 1665-1672 ◽  
Author(s):  
Jaroslava Horáčková ◽  
Vojeslav Štěrba
Keyword(s):  
Carboxylic Acid ◽  
Rate Constant ◽  
Kinetics Of

Kinetics have been studied of gradual replacement of 4-methoxyphenylazo groups in 2,6-dioxo-5(3)-(4-methoxyphenylazo)-3(5)-(4-methoxyphenylhydrazono)-1,2,3,6-tetrahydropyridine-4-carboxylic acid (IIIa) by 4-nitrophenylazo groups using the reaction with 4-nitrobenzenediazonium cation (IIc) in acetate and phosphate buffers. The rate constant of replacement of the second methoxyphenylazo group is lower by a factor of ca 60. From the experimentally found pKa values of the corresponding azohydrazone compounds with methoxy, chloro, or nitro substituent at 4-position (IIIa - IIIf) it has been concluded that the 5(3)-(4-methoxyphenylazo)-3(5)-(4-nitrophenylhydrazono) derivative is formed in the first step.

scholarly journals Propylphosphonic acid anhydride–mediated amidation of Morita–Baylis–Hillman–derived indolizine-2-carboxylic acids

2021 ◽  
pp. 174751982098715
Author(s):  
Khethobole C Sekgota ◽  
Michelle Isaacs ◽  
Heinrich C Hoppe ◽  
Ronnett Seldon ◽  
Digby F Warner ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Coupling Agent ◽  
Methyl Esters ◽  
Acid Anhydride

Propylphosphonic acid anhydride has been successfully used as a coupling agent in the synthesis of a series of indolizine-2-carboxamido derivatives from indolizine-2-carboxylic acid and its 3-acetylated analogue. The acid substrates were obtained by saponification of the corresponding methyl esters produced, in turn, selectively and efficiently, by time-controlled cyclisation of a single Morita–Baylis–Hillman adduct. Various amino and hydrazino compounds with medicinal potential have been used to prepare indolizine-2-carboxamido and hydrazido derivatives.

S/X ratio impacts the profile and kinetics of carboxylic acids production from the acidogenic fermentation of dairy wastewater

2021 ◽  
pp. 117605
Author(s):  
Amanda de Sousa e Silva ◽  
Tasso Jorge Tavares Ferreira ◽  
Naassom Wagner Sales Morais ◽  
Erlon Lopes Pereira ◽  
André Bezerra dos Santos
Keyword(s):  
Carboxylic Acids ◽  
Dairy Wastewater ◽  
Acidogenic Fermentation ◽  
Kinetics Of

Biological Activity of Novel N-Substituted Amides of endo-3- (3-Methylthio-1,2,4-triazol-5-yl)bicyclo[2.2.1]hept-5-ene-2- carboxylic Acid and N-Substituted Amides of 1-(5-Methylthio- 1,2,4-triazol-3-yl)cyclohexane-2-carboxylic Acids

2012 ◽  
Vol 67 (3-4) ◽  
pp. 123-128
Author(s):  
Anna Pachuta-Stec ◽  
Urszula Kosikowska ◽  
Anna Chodkowska ◽  
Monika Pitucha ◽  
Anna Malm ◽  
...  
Keyword(s):  
Biological Activity ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Condensation Reaction ◽  
Primary Amines ◽  
Pharmacological Activities

N-Substituted amides of endo-3-(3-methylthio-1,2,4-triazol-5-yl)bicyclo[2.2.1]hept-5-ene- 2-carboxylic acid and 1-(5-methylthio-1,2,4-triazol-3-yl)cyclohexane-2-carboxylic acid were prepared by the condensation reaction of endo-S-methyl-N1-(bicyclo[2.2.1]hept-5-ene-2,3- dicarbonyl)isothiosemicarbazide and S-methyl-N1-(cyclohexane-2,3-dicarbonyl)isothiosemicarbazide with primary amines. The synthesized compounds were screened for their microbiological and pharmacological activities

scholarly journals Comparison of Three Solid Phase Materials for the Extraction of Carboxylic Acids from River Water Followed by 2D GC × GC-TOFMS Determination

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
G. O. Bosire ◽  
J. C. Ngila ◽  
H. Parshotam
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Natural Organic Matter ◽  
Solid Phase ◽  
Cooling Water ◽  
Raw Water ◽  
Aliphatic Carboxylic Acid ◽  
Hydrophobic Nature ◽  
Relationship Of

The extraction and determination of aliphatic and aromatic carboxylic acids as well as their influence on the aromaticity and molecularity relationship of natural organic matter (NOM) in water are reported in this study. Three solid phase extraction (SPE) sorbents were used and their extraction efficiencies evaluated after chromatographic determinations (using gas chromatography with a time of flight mass spectrometer (GC × GC-TOFMS) and liquid chromatography with organic carbon detector (LC-OCD)). More than 42 carboxylic acids were identified in raw water from the Vaal River, which feeds the Lethabo Power Generation Station, South Africa, with cooling water. The aromatic carboxylic acid efficiency (28%) was achieved by using Strata™X SPE while the highest aliphatic carboxylic acid efficiency (92.08%) was achieved by silica SPE. The hydrophobic nature of NOM in water depends on the nature of organic compounds in water, whether aromatic or aliphatic. The LC-OCD was used to assess the hydrophobicity levels of NOM as a function of these carboxylic acids in cooling water. The LC-OCD results showed that the aromatic nature of NOM in SPE filtered water followed the order Silica>Strata X>C-18. From the results, the hydrophobicity degree of the samples depended on the type and number of carboxylic acids that were removed by the SPE cartridges.

BASIC ESTERS OF SUBSTITUTED PYRIMIDINE-4-CARBOXYLIC ACIDS

1956 ◽  
Vol 34 (10) ◽  
pp. 1444-1446 ◽  
Author(s):  
Gordon A. Grant ◽  
Carl Von Seemann ◽  
Stanley O. Winthrop
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Mucochloric Acid

A number of β-dialkylaminoethyl esters of 2,5-disubstituted pyrimidine-4-carboxylic acids have been synthesized and characterized as their hydrochlorides and in some cases as their methobromide and methiodide salts. Mucochloric acid has been condensed with S-methylisothiouronium sulphate to give 2-methylthio-5-chloropyrimidine-4-carboxylic acid, and the corresponding 5-bromo- acid has been converted to the 5-amino-acid.

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