Electrochemical oxidation of methylindoles

1981 ◽  
Vol 46 (13) ◽  
pp. 3278-3284 ◽  
Author(s):  
Miroslav Janda ◽  
Jan Šrogl ◽  
Petr Holý
Keyword(s):  
Electrochemical Oxidation ◽  
Ammonium Bromide ◽  
Platinum Anode

Electrochemical oxidation of 1-methylindole (I), 1,3-dimethylindole (II) and 1,2-dimethylindole (III) on a platinum anode in methanol, containing ammonium bromide, was studied. A more profound oxidation as compared with benzofuran or benzothiophene derivatives is indicated by the obtained products: 1-methyl-2,2-bis(1-methylindol-3-yl)-3-indolinone (IV), 1,1'-dimethyl-Δ3,3-biindolin-2,2'-dione (V), 3,3-dibromo-1-methyl-2-indolinone (VI), 3,3,5-tribromo-1-methyl-2-indolinone (VII), 3-bromo-1-methyl-2,3-indoledione (VIII), 3-methoxy-1,3-dimethyl-2-indolinone (IX), 3-hydroxy-1,3-dimethyl-2-indolinone (X), 3,5-dibromo-1,3-dimethyl-2-indolinone (XI) and 3-bromo-1,2-dimethylindole (XII). The ratio of the products can be significantly influenced by the electrolysis conditions. The oxidation takes place in positions 2 and 3 of the indole molecule, the position 2 influencing decisively the oxidation path.

Remediation of Water Contaminated with Pesticides by Indirect Electrochemical Oxidation Process Electro-Fenton

2008 ◽  
Vol 11 (2) ◽  
Author(s):  
Aida Kesraoui Abdessalem ◽  
Nihal Oturan ◽  
Nizar Bellakhal ◽  
Mohamed Dachraoui ◽  
Mehmet A. Oturan
Keyword(s):  
Aqueous Solutions ◽  
Hydroxyl Radical ◽  
Electrochemical Oxidation ◽  
Acidic Medium ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Advanced Oxidation ◽  
Fenton Process ◽  
Carbon Felt ◽  
Platinum Anode

AbstractThe mineralization of pesticides chlortoluron, carbofuran and bentazone aqueous solutions in acidic medium of pH 3 was studied by electro-Fenton process using a carbon felt cathode and a platinum anode. This advanced oxidation process allows the formation of hydroxyl radical (

Electrochemical oxidation of 1,1-dihydroxy-4-methylcyclohexane on platinum anode. Synthesis of 3,12-dimethyl-7,8,15,16-tetraoxadispiro[5.2.5.2]hexadecane

2011 ◽  
Vol 47 (2) ◽  
pp. 234-237 ◽  
Author(s):  
M. D. Vedenyapina ◽  
A. O. Terent’ev ◽  
M. M. Platonov ◽  
A. M. Skundin ◽  
A. A. Vedenyapin ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Platinum Anode

scholarly journals Studies of Biologically Active Heterocycles: Synthesis, Characterization and Antimicrobial Activity of Some 5-Substitutd-2-Amino-1,3,4-Oxadiazoles

1970 ◽  
Vol 9 (1) ◽  
pp. 53-59
Author(s):  
Sanjeev Kumar
Keyword(s):  
Antifungal Activity ◽  
Electrochemical Oxidation ◽  
Room Temperature ◽  
Antibacterial Agents ◽  
Antimicrobial Agents ◽  
Biologically Active ◽  
Structural Assignment ◽  
Platinum Anode ◽  
Controlled Potential Electrolysis ◽  
Controlled Potential

In the present study, 5-substituted-2-amino-1,3,4-oxadiazoles (4a-k) have been synthesized by the electrochemical oxidation of semicarbazones (3a-k) using platinum anode at room temperature under controlled potential electrolysis in an undivided cell assembly. The structural assignment of these compounds (4a-k) has been made on the basis of elemental analysis, IR, 1H NMR and 13C NMR. The synthesized compounds were screened for their inhibiting activity against Klebsilla penumoniae, Escherichia coli, Bassilus subtilis and Streptococcus aureus and antifungal activity against Aspergillus niger and Crysosporium pannical and results have been compared with the standard antibacterial agents, Streptomycin and antifungal drug, Griseofulvin. The Compounds exhibited significant antibacterial activity and antifungal activity. Key words: Electrochemical oxidation; controlled potential; 5-substituted-2-amino-1,3,4-oxadiazole; semicarbazone; antimicrobial agents DOI: 10.3329/dujps.v9i1.7434 Dhaka Univ. J. Pharm. Sci. 9(1): 53-59 2010 (June)

scholarly journals Electrochemical conversion pathways and existing morphology of arsenic(III) in anode-cathode separated electrolytic cells

2020 ◽  
Author(s):  
Yanyan Qin ◽  
Yanping Cui ◽  
Zhengwei Zhou ◽  
Ya Gao ◽  
Lidan Lei ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Low Voltage ◽  
Electrolytic Cell ◽  
Alkaline Media ◽  
Acid Electrolyte ◽  
Electrolytic Cells ◽  
Electrochemical Conversion ◽  
Theoretical Support ◽  
Platinum Anode

Abstract To explore the electrochemical conversion of arsenic at different voltages and pH, an open separated electrolytic cell with a platinum anode and a graphite cathode was selected for this paper. The form and concentration of arsenic in the anodic cell and cathodic cell were detected. Experimental results proved that at 40.0 V, As(III) in an acid electrolyte in the cathodic cell was firstly mainly reduced to AsH3 with trace As(0) as intermediate. As the electrolysis time arrived at 27 min, pH in the cathodic cell jumped suddenly from acidity to alkalinity, accompanied by the majority of the remaining As(III) converting to As(V) for an instant. As time went on, As(III) and As(V) remained almost unchanged at the ratio of 1:3, and the reduction of As(III) became extremely weak in the alkaline environment. When pH in the cathodic tank was adjusted to keep it acid, As(III) was eventually converted to AsH3. Compared with high voltage, at a low voltage of 1.0 V the cathode failed to achieve the potential of As(III) reduction and As(III) was eventually oxidized to As(V) in the acid catholyte. Electrochemical oxidation of As(III) in the open cathodic cell was likely caused by in-situ generation of peroxide from electrochemical reduction of O2. Theoretical support for electrochemical oxidation of As(III) on a carbon cathode in neutral and weak alkaline media is provided in this study.

Retarding of electrochemical oxidation of formate on the platinum anode by a coat of Nafion membrane

2014 ◽  
Vol 272 ◽  
pp. 303-310 ◽  
Author(s):  
Rui Zhang ◽  
Weixin Lv ◽  
Guanghua Li ◽  
Mohammed Adnan Mezaal ◽  
Xiaojing Li ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Nafion Membrane ◽  
Platinum Anode

Gum arabic helps prepare better lacey polymer films for specimen support in electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 240-241
Author(s):  
Shailesh R. Sheth ◽  
Jayesh R. Bellare
Keyword(s):  
Electron Microscopy ◽  
Polymer Films ◽  
Gum Arabic ◽  
Complete Removal ◽  
Ammonium Bromide ◽  
Release Agent ◽  
Astigmatism Correction ◽  
Long Time ◽  
Micro Holes ◽  
Cetyl Trimethyl Ammonium

Specimen support and astigmatism correction in Electron Microscopy are at least two areas in which lacey polymer films find extensive applications. Although their preparation has been studied for a very long time, present techniques still suffer from incomplete release of the film from its substrate and presence of a large number of pseudo holes in the film. Our method ensures complete removal of the entire lacey film from the substrate and fewer pseudo holes by pre-treating the substrate with Gum Arabic, which acts as a film release agent.The method is based on the classical condensation technique for preparing lacey films which is essentially deposition of minute water or ice droplets on the substrate and laying the polymer film over it, so that micro holes are formed corresponding to the droplets. A microscope glass slide (the substrate) is immersed in 2.0% (w/v) aq. CTAB (cetyl trimethyl ammonium bromide)-0.22% (w/v) aq.

The Effects of Amines on the Esterase Activities of Thrombin and Thrombokinase and on Several Clotting Tests

1974 ◽  
Vol 31 (02) ◽  
pp. 309-318
Author(s):  
Phyllis S Roberts ◽  
Raphael M Ottenbrite ◽  
Patricia B Fleming ◽  
James Wigand
Keyword(s):  
Choline Chloride ◽  
Polymerization Process ◽  
Ammonium Bromide ◽  
Bovine Thrombin ◽  
One Stage ◽  
Human Proteins ◽  
Rate Of Hydrolysis ◽  
The One ◽  
Hydrolysis Of Esters ◽  
Hydrolysis Of

Summary1. Choline chloride, 0.1 M (in 0.25 M Tris. HCl buffer, pH 7.4 or 8.0, 37°), doubles the rate of hydrolysis of TAME by bovine thrombokinase but has no effect on the hydrolysis of this ester by either human or bovine thrombin. Only when 1.0 M or more choline chloride is present is the hydrolysis of BAME by thrombokinase or thrombin weakly inhibited. Evidence is presented that shows that these effects are due to the quaternary amine group.2. Tetramethyl ammonium bromide or chloride has about the same effects on the hydrolysis of esters by these enzymes as does choline chloride but tetra-ethyl, -n.propyl and -n.butyl ammonium bromides (0.1 M) are stronger accelerators of the thrombokinase-TAME reaction and they also accelerate, but to a lesser degree, the thrombin-TAME reaction. In addition, they inhibit the hydrolysis of BAME by both enzymes. Their effects on these reactions, however, do not follow any regular order. The tetraethyl compound is the strongest accelerator of the thrombokinase-TAME reaction but the tetra-ethyl and -butyl compounds are the strongest accelerators of the thrombin-TAME reaction. The ethyl and propyl compounds are the best (although weak) inhibitors of the thrombokinase-BAME and the propyl compound of the thrombin-BAME reactions.3. Tetra-methyl, -ethyl, -n.propyl and -n.butyl ammonium bromides (0.01 M) inhibit the clotting of fibrinogen by thrombin (bovine and human proteins) at pH 7.4, imidazole or pH 6.1, phosphate buffers and they also inhibit, but to a lesser degree, a modified one-stage prothrombin test. In all cases the inhibition increases regularly as the size of the alkyl group increases from methyl to butyl. Only the ethyl com pound (0.025 M but not 0.01 M), however, significantly inhibits the polymerization of bovine fibrin monomers. It was concluded that inhibition of the fibrinogen-thrombin and the one-stage tests by the quaternary amines is not due to any effect of the com pounds on the polymerization process but probably due to inhibition of thrombin’s action on fibrinogen by the quaternary amines.

Using of modified-bentonite as low-cost sorbent for removal of methylene blue dye from aqueous solution

2020 ◽  
Vol 27 (2) ◽  
pp. 45-54
Author(s):  
Saraa Muwafaq Ibrahim ◽  
Ziad T. Abd Ali
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Silanol Group ◽  
Infrared Spectrometry ◽  
Blue Dye ◽  
Ammonium Bromide ◽  
Vibration Band ◽  
Order Kinetic ◽  
Methylene Blue Dye ◽  
Modified Bentonite

Batch experiments have been studied to remove methylene blue dye (MB) from aqueous solution using modified bentonite. The modified bentonite was synthesized by replacing exchangeable calcium cations in natural bentonite with cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The characteristics of modified bentonite were studied using different analysis such as Scanning electronic microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and surface area. Where SEM shows the natural bentonite has a porous structure, a rough and uneven appearance with scattered and different block structure sizes, while the modified bentonite surface morphology was smooth and supplemented by a limited number of holes. On other hand, (FTIR) analysis that proved NH group aliphatic and aromatic group of MB and silanol group are responsible for the sorption of contaminate. The organic matter peaks at 2848 and 2930 cm-1 in the spectra of modified bentonite which are sharper than those of the natural bentonite were assigned to the CH2 scissor vibration band and the symmetrical CH3 stretching absorption band, respectively, also the 2930 cm-1 peak is assigned to CH stretching band. The batch study was provided the maximum removal efficiency (99.99 % MB) with a sorption capacity of 129.87 mg/g at specified conditions (100 mg/L, 25℃, pH 11 and 250rpm). The sorption isotherm data fitted well with the Freundlich isotherm model. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules.

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