scholarly journals Synthesis, characteristic fragmentation patterns, and antibacterial activity of new azo compounds from the coupling reaction of diazobenzothiazole ions and acetaminophen

2021 ◽  
Vol 27 (1) ◽  
pp. 79-89
Author(s):  
Joseph Tsemeugne ◽  
Pamela Kemda Nangmo ◽  
Pierre Mkounga ◽  
Jean De Dieu Tamokou ◽  
Iréne Chinda Kengne ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Analytical Data ◽  
Coupling Reaction ◽  
Azo Compounds ◽  
Electrophilic Aromatic Substitution ◽  
Spectroscopic Techniques ◽  
Aromatic Substitution ◽  
Chemical Structures ◽  
Characteristic Fragmentation ◽  
Fragmentation Patterns

Abstract In this study, a series of azobenzothiazole dyes 4 were synthesized via diazotization of substituted benzothiazole derivatives followed by azo coupling with acetaminophen. The chemical structures of all synthesized compounds were confirmed using analytical data and spectroscopic techniques, including UV-visible, IR, mass spectra, and 1H- and 13C-NMR. The in situ formed diazobenzothiazole ions regiospecifically react with acetaminophen derivatives in the Hollemann-guided electrophilic aromatic substitution mechanism. The regio-orientations were established, on the one hand, by a rigorous interpretation of 1H-NMR spectra and, on the other hand, by the characteristic fragmentation patterns observed on the electrospray mass spectra. In the cases of 4a and 4b, multisubstitutions occurred. The antimicrobial activity of compound 4, along with all the starting materials, was investigated on Pseudomonas aeruginosa PA01, Staphylococcus aureus 18, Escherichia coli 64R, and S. aureus ATCC 25923. The results showed that this skeletal framework exhibited marked potency as antibacterial agents. The most active antibacterial agent against both targeted organisms was compound 4a′.

N=N Vibrational Frequencies and Fragmentation Patterns of Substituted 1-Aryl-3,3-Dialkyl-Triazenes: Comparison with other High-Nitrogen Compounds

1993 ◽  
Vol 47 (7) ◽  
pp. 986-993 ◽  
Author(s):  
F. Zimmermann ◽  
Th. Lippert ◽  
Ch. Beyer ◽  
J. Stebani ◽  
O. Nuyken ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Mass Spectra ◽  
Valence Vibration ◽  
Vibrational Frequencies ◽  
Substitution Pattern ◽  
Ft Ir ◽  
Characteristic Fragmentation ◽  
Fragmentation Patterns ◽  
Substituted 1 ◽  
Ir And Raman

The influence of substitution pattern and electronic structure on the N=N stretching frequencies of compounds containing three to six linearly connected nitrogen atoms has been investigated by FT-IR and Raman spectroscopy. For a series of 1-phenyl-3,3-dialkyl-triazenes, Phe-N1=N2-N3 R2, shifts in the two valence vibrations of the triazeno group are studied with respect to the type and position of substituents at the aromatic ring, and for various alkyl substituents at N3. The N1=N2 stretching frequency is lowered by electron-withdrawing substituents at the aromatic ring; this effect is most pronounced for para-positioned substituents. A decrease in the N1=N2 bond order, and of the associated valence vibration, is also observed upon introduction of heavier N3-alkyl substituents, due to an inductive effect. Changes in vibrational frequencies are correlated with characteristic fragmentation patterns in the mass spectra of these compounds, where two degradation routes subsequent to ionization at the nitrogen atoms N1 and N2 have been observed. For the investigated pentazadiene derivatives, a weaker dependence of the N=N vibrational frequencies on the substituents is found. Mass spectra are interpreted in terms of two typical fragmentation pathways, involving a McLafferty rearrangement.

Some Aspects of the Mass Spectra of.N-Nitrosamines

1971 ◽  
Vol 49 (9) ◽  
pp. 1367-1371 ◽  
Author(s):  
J. W. ApSimon ◽  
J. D. Cooney
Keyword(s):  
Mass Spectra ◽  
Accurate Mass ◽  
Mass Measurements ◽  
Molecular Ion ◽  
Accurate Mass Measurements ◽  
Characteristic Fragmentation ◽  
Fragmentation Patterns

The mass spectra of seven cyclic N-nitrosamines were examined for characteristic fragmentation patterns. Accurate mass measurements on three of the compounds indicated that the M-17 and M-30 peaks resulted from molecular ion losses of •OH and •NO respectively. The loss of • OH was rationalized in terms of a McLafferty-type rearrangement.

scholarly journals Separation and structural analysis of vinyl- and isovinyl-azobilirubin derivatives

1971 ◽  
Vol 125 (2) ◽  
pp. 585-597 ◽  
Author(s):  
F. H. Jansen ◽  
M. S. Stoll
Keyword(s):  
Proton Magnetic Resonance ◽  
Mass Spectra ◽  
Methyl Esters ◽  
Coupling Reaction ◽  
Azo Compounds ◽  
Side Chain ◽  
Diazonium Salts ◽  
Side Reactions ◽  
Group 2

The coupling reaction of bilirubin with the diazonium salts of ethyl anthranilate or of aniline yields two isomeric azopigments. These can be separated by t.l.c. as their methyl esters. The mass spectra of each pair of azopigments are very similar, showing that they are isomers. Proton-magnetic-resonance spectrometric studies show that they differ in the positions of the substituents on the pyrrolenone end ring; in one compound the methyl and vinyl groups are interposed compared with the other compound. These azo compounds were used as reference standards for determination of the site of conjugation in bilirubin monoglucuronide prepared enzymically. Analysis showed that conjugation occurs at the carboxyethyl side chain of both sides of the bilirubin molecule. During the preparation of the ethyl anthranilate reference compounds a series of minor azopigments were isolated by t.l.c. Analysis of the mass spectra of many of these showed that three side reactions can occur: (1) methylation of the imide carbonyl group; (2) addition of methanol or water to the vinyl substituent; (3) transmethylation of the ethoxycarbonyl group.

scholarly journals Coumarin phthalonitriles: Synthesis and cation binding properties

2015 ◽  
Vol 11 (4) ◽  
pp. 3512-3518 ◽  
Author(s):  
Rawdha Medyouni ◽  
Olfa Naouali ◽  
Naceur HAMDI ◽  
Lassaad Baklouti
Keyword(s):  
Mass Spectra ◽  
Biological Activities ◽  
Earth Metal ◽  
Cation Binding ◽  
Nucleophilic Aromatic Substitution ◽  
Uv Spectrophotometry ◽  
Spectroscopic Techniques ◽  
Aromatic Substitution ◽  
Binding Properties ◽  
Heavy Metal Cations

Coumarin possess a number of biological activities like anticoagulant, antimicrobial, anti-inflammatory, analgesic,antioxidant, anticancer, antiviral, antimalarial etc. Coumarin belongs to a group as benzopyrones, which consists of a benzene ring joined to a pyrone nucleus. In this work, new coumarin phtalonitriles derivatives were synthesized and characterized via spectroscopic techniques IR, 1H NMR, 13C NMR, mass spectra and elemental analysis.The synthesis of coumarin phtalonitriles resulting from a nucleophilic aromatic substitution reaction between 4-nitrophtalonitrile and coumarins derivatives. The complexing properties of the coumarin derivatives toward alkali metal, alkaline earth metal, some transition metals and some heavy metal cations have been investigated in acetonitrile by means of UV spectrophotometry absorption and conductivity methods. Thus, the stoichiometry of the complexes formed and their stability constants were determined

Flavan derivatives. XXV. Mass spectra of 3-hydroxyflavanones, flavan-3-ols, and flavan-3,4-diols

1968 ◽  
Vol 21 (12) ◽  
pp. 3025 ◽  
Author(s):  
JW Clark-Lewis
Keyword(s):  
Mass Spectra ◽  
Hydrogen Transfer ◽  
Diels Alder ◽  
Hydroxyl Group ◽  
Mass Spectral Data ◽  
Insertion Technique ◽  
Mass Spectral ◽  
Marked Enhancement ◽  
Characteristic Fragmentation ◽  
Fragmentation Patterns

Mass spectral data are reported for eight 3-hydroxyflavanones, ten flavan-3-ols, and twelve flavan-3,4-diol derivatives. The principal fragmentation of each of these three classes of compound yields ions derived by retro Diels-Alder fission of the heterocyclic nucleus, accompanied in the case of 3-hydroxyflavanones and flavan-3-ols by hydrogen transfer from the 3-hydroxyl group to the A ring fragment. Deuteration experiments with flavan-3-ols confirmed the origin of the hydrogen atom transferred. Flavan-3,4-diols show two characteristic fragmentation patterns depending on the insertion technique. Mass spectra obtained by indirect insertion of flavan-3,4-diols showed a very marked enhancement of the intensities of the M-18 and M-18-28 peaks, and of their fragmentation ions, compared with spectra obtained by direct insertion.

Synthesis, Antimicrobial Evaluation of Some New 1, 3, 4-Thiadiazoles and 1, 3, 4- Thiadiazines

2018 ◽  
Vol 15 (8) ◽  
pp. 1161-1170 ◽  
Author(s):  
Ameen Ali Abu-Hashem ◽  
Rasha A. M. Faty
Keyword(s):  
Antimicrobial Activity ◽  
Mass Spectra ◽  
High Yield ◽  
Spectroscopic Techniques ◽  
Chemical Structures ◽  
Antibiotic Drugs ◽  
Antimicrobial Evaluation ◽  
Bacteria And Fungi ◽  
New Compounds

Background: 1, 3, 4-thiadiazoles, 1, 3, 4-thiadiazines and thienopyrimidines have newly attracted attention due to their forceful pharmacological activities. They showed antimicrobial, antiviral, analgesic and anti-inflammatory properties. Objective: The aim of this research is to synthesize new thiadiazolothienopyrimidines (2-10), thienopyrimidothiadiazines (11-15), quinoxaline-thienopyrimidinones (16) and thienopyrimido- thiadiazinoquinoxalinones (17) via effectual high yield procedure for assessing their antimicrobial activity. Method: A series of new 1, 3, 4-thiadiazolothienopyrimidines, thienopyrimidothiadiazines and thienopyrimidothiadiazinoquinoxalinones was prepared from 6-acetyl-3-amino-5-methyl-2-thioxo-2, 3-dihydrothieno [2, 3-d] pyrimidin-4(1H)-one (1) as the beginning material. Results: The 1, 3, 4-thiadiazoles, 1, 3, 4-thiadiazines derivatives (1-17) were synthesized in adequate to good yields (60-85%) in a stepwise effectual procedure under condition. The chemical structures of these new compounds were confirmed via many spectroscopic techniques as UV, IR, NMR, mass spectra and elemental analysis. In vitro, antimicrobial was evaluated for the synthesized compounds using minimal inhibitory concentration of these compounds against bacteria and fungi. Conclusion: The 1, 3, 4-thiadiazole and 1, 3, 4-thiadiazine derivatives (15-17) exhibited higher antimicrobial activity (Gram-positive, Gram-negative bacteria and fungi) compared with the standard antibiotic drugs; Levofloxacin (Tavanic) and Nystatin.

Triazole-Anil and Triazol-Azo Reagents (Creation, Spectral Categorization, Scanning Microscopy, Thermal Analysis)

2021 ◽  
Vol 19 (11) ◽  
pp. 84-94
Author(s):  
Aymen Abdul Rasool Jawad ◽  
Dr. Nagham Mahmood Aljamali
Keyword(s):  
Mass Spectra ◽  
Thermal Study ◽  
Spectroscopic Techniques ◽  
Electron Pairs ◽  
Chemical Structures ◽  
Environmental Models ◽  
Chemical Measurements ◽  
Physico Chemical ◽  
Anti Cancer ◽  
Scanning Electron

The last decades of this century witnessed a wide interest in three heterogeneous compounds, especially nitrogen atoms, which were represented by triazole rings and their derivatives, whose effects were studied in the widest medical and pharmaceutical journals and as anti-cancer agents and other groups that are characterized by the presence of electronic pairs, which have given greater importance for this reason. In order to increase the effectiveness of any compound, it must include in its composition active groups, donor groups, or electron pairs, and this has been proven by researchers in biochemistry, coordination research, reagent chemistry, reagents, analytical chemistry, estimation of elements and ions in river water and environmental models. Extensive studies have been conducted for the reagents under study to determine their chemical structures through microscopic technical examinations, spectroscopic techniques (Uv-Vis, FT.IR, H.NMR, Mass)–spectra, also Analytical studies like: {Thermal study, TLC–Technique, Scanning Electron Microscopy (FESEM)} and other physico-chemical measurements.

scholarly journals Synthesis, Characterization and Antimicrobial Evaluation of New Azo Compounds Derived from Sulfonamides and Isatin Schiff Base

2020 ◽  
Vol 10 (01) ◽  
pp. 150-155
Author(s):  
May M. Jawad Al-Mudhafar ◽  
Rana A. Kamoon ◽  
Tagreed N-A Omar
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Schiff Base ◽  
Candida Albicans ◽  
Coupling Reaction ◽  
Azo Compounds ◽  
Diffusion Method ◽  
Elemental Analysis Data ◽  
Chemical Structures

The present study deals with the synthesis of four different azo-azomethine derivatives; this is done by two steps; the first step is diazotization of sulfonamides (sulfanilamide, sulfacetamide, sulfamethoxazole, and sulfadiazine) separately, followed by the second step; the coupling reaction of diazotized compounds with isatin bis-Schiff base named 3-((4-nitrobenzylidene) hydrazono)indolin-2-one. The later one (bis-Schiff base) was synthesized by the reaction of 3-hydrazono-indolin-2-one with p-nitrobenzaldehyde. The chemical structures of newly synthesized compounds were approved on the basis of their FTIR, 1H-NMR, and CHNS elemental analysis data results. The synthesized azo compounds were tested in vitro for their antimicrobial potential using well diffusion method. All the target compounds were clearly inhibited Escherichia coli and Candida albicans, while only compounds 2b and 2c show antibacterial activity against Pseudomonas aeruginosa. The most active compound among the prepared azo compounds against Escherichia coli, Pseudomonas aeruginosa, and Candida albicans is compound 2b.

Electron impact studies. XII. Mass spectra of substituted imidazoles

1967 ◽  
Vol 20 (8) ◽  
pp. 1613 ◽  
Author(s):  
JH Bowie ◽  
RG Cooks ◽  
S Lawesson ◽  
G Schroll
Keyword(s):  
Mass Spectrometry ◽  
Structure Elucidation ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Skeletal Rearrangement ◽  
Mass Measurements ◽  
Exact Mass ◽  
Metastable Ions ◽  
Characteristic Fragmentation ◽  
Fragmentation Patterns

The mass spectra of 37 imidazoles are reported and discussed. The spectra exhibit pronounced molecular ions and characteristic fragmentation patterns. The fragmentation modes have been substantiated by deuterium labelling, exact mass measurements, and appropriate metastable ions. Skeletal rearrangement fragments are rare in these spectra; consequently mass spectrometry is useful for structure elucidation of imidazoles.

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