Possible competitive modes of decarboxylation in the annulation reactions of ortho-substituted anilines and arylglyoxylates

2021 ◽  
Author(s):  
Joydev K. Laha ◽  
Surabhi Panday ◽  
Monika Tomar ◽  
Ketul V. Patel
Keyword(s):  
Nitrogen Heterocycles ◽  
Substituted Anilines ◽  
Competitive Modes ◽  
Tandem Synthesis

Annulation reactions of ortho-substituted anilines and arylglyoxylates to the tandem synthesis of nitrogen heterocycles in the presence of K2S2O8 have been investigated, which occur via decarboxylation before or after the reaction with anilines.

Implications of dynamic imine chemistry for the sustainable synthesis of nitrogen heterocycles via transimination followed by intramolecular cyclisation

2016 ◽  
Vol 14 (8) ◽  
pp. 2473-2479 ◽  
Author(s):  
Joydev K. Laha ◽  
K. S. Satyanarayana Tummalapalli ◽  
Krupal P. Jethava
Keyword(s):  
Nitrogen Heterocycles ◽  
Substituted Anilines

An application of dynamic imine chemistry to the sustainable synthesis of N-heterocycles from N-aryl benzylamines or imines and ortho-substituted anilines is described.

Potassium Periodate Mediated Oxidative Cyclodesulfurization toward Benzofused Nitrogen Heterocycles

Synthesis ◽  
2020 ◽  
Vol 52 (13) ◽  
pp. 1981-1990
Author(s):  
Mookda Pattarawarapan ◽  
Chuthamat Duangkamol ◽  
Wong Phakhodee
Keyword(s):  
Intramolecular Cyclization ◽  
Oxidative Coupling ◽  
Nitrogen Heterocycles ◽  
Coupling Reactions ◽  
Substituted Anilines ◽  
Potassium Periodate ◽  
High Yields ◽  
Quinazolinone Derivatives ◽  
Oxidative Coupling Reactions

A convenient oxidative cyclodesulfurization method toward the synthesis of benzofused nitrogen heterocycles using inexpensive and readily available potassium periodate as an oxidant was developed. Upon treating isothiocyanates with ortho-substituted anilines bearing N,N-, N,O-, and N,S-bis-nucleophiles, followed by an intramolecular cyclization of the in situ generated monothioureas, substituted 2-aminobenzazole series were rapidly accessible in good to excellent yields. The protocol can accommodate various substituents on both substrates while allowing more efficient, greener, and operational simpler process relative to other oxidative coupling reactions. Tetracyclic quinazolinone derivatives were also afforded in high yields in a single preparative step and chromatography-free.

Reaction with acetic anhydride as a method for estimating the basicity of exocyclic amino groups in nitrogen heterocycles

1984 ◽  
Vol 37 (8) ◽  
pp. 1625 ◽  
Author(s):  
LW Deady ◽  
WL Finlayson
Keyword(s):  
Acetic Anhydride ◽  
Nitrogen Heterocycles ◽  
Amino Group ◽  
Amino Groups ◽  
Substituted Anilines ◽  
Pka Values

Relative rates for acetylation of various anilines and amino heterocycles with acetic anhydride in pyridine were determined by a competition method. From a Bronsted plot of reactivity against basicity for the anilines, and by considering the heterocycles as substituted anilines, pKa values for the amino group in a variety of heterocycles have been obtained.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Evaluation of Antioxidant and Antitumor Activities of Some Prepared Nitrogen Heterocycles

2011 ◽  
Vol 3 (7) ◽  
pp. 106-110
Author(s):  
Mohamed Abd El-Moneim ◽  
◽  
Ibrahim M El-Deen ◽  
Wessam Abd El-Fattah
Keyword(s):  
Nitrogen Heterocycles ◽  
Antitumor Activities

Analysis of Aromatic Amines in Industrial Wastewater by Capillary Gas Chromatography-Mass Spectrometry

2000 ◽  
Vol 35 (2) ◽  
pp. 245-262 ◽  
Author(s):  
Francis I. Onuska ◽  
Ken A. Terry ◽  
R. James Maguire
Keyword(s):  
Gas Chromatography ◽  
Aromatic Amines ◽  
Methylene Chloride ◽  
Solid Phase ◽  
Stationary Phases ◽  
Gas Chromatography Mass Spectrometry ◽  
Substituted Anilines ◽  
Environmental Media ◽  
Solid Phase Extraction Cartridge ◽  
Wide Range

Abstract The analysis of aromatic amines, particularly benzidines, at trace levels in environmental media has been difficult because of the lack of suitable deactivated capillary column stationary phases for gas chromatography. This report describes the use of an improved type of column as well as a method for the analysis of anilines and benzidines in water, wastewater and sewage samples. Extraction procedures are applicable to a wide range of compounds that are effectively partitioned from an aqueous matrix into methylene chloride, or onto a solid-phase extraction cartridge. The extracted analytes are also amenable to separation on a capillary gas chromatographic column and transferable to the mass spectrometer. These contaminants are converted to their N-trifluoroacetyl derivatives. Aniline and some substituted anilines, and 3,3’-dichlorobenzidine and benzidine were determined in 24-h composite industrial water, wastewater, primary sludge and final effluent samples at concentrations from 0.03 up to 2760 µg/L.

Naturally Occurring Organic Acid-catalyzed Facile Diastereoselective Synthesis of Biologically Active (E)-3-(arylimino)indolin-2-one Derivatives in Water at Room Temperature

2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  
Keyword(s):  
Room Temperature ◽  
Biologically Active ◽  
Environmentally Benign ◽  
Diastereoselective Synthesis ◽  
Substituted Anilines ◽  
Reaction Conditions ◽  
Naturally Occurring ◽  
Acid Catalyzed ◽  
Reaction Media ◽  
Column Chromatographic

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.

Sign in / Sign up

Export Citation Format

Share Document