scholarly journals Synthesis of Some 2-Amino-5-substituted-1,3,4-oxadiazole Derivatives in the Acetic Acid

2011 ◽  
Vol 8 (s1) ◽  
pp. S448-S454 ◽  
Author(s):  
Sanjeev Kumar
Keyword(s):  
Acetic Acid ◽  
Room Temperature ◽  
Platinum Electrode ◽  
Supporting Electrolyte ◽  
Saturated Calomel Electrode ◽  
Reference Electrode ◽  
Lithium Perchlorate ◽  
Environmentally Benign ◽  
Controlled Potential ◽  
Oxadiazole Derivatives

An environmentally benign method for the preparation of 2-amino-5-substituted-1,3,4-oxadiazoles (1a-n) at platinum electrode through the electrooxidation of semicarbazone at room temperature is reported. The electrolysis were carried out at controlled potential in acetic acid solvent using lithium perchlorate as supporting electrolyte in an undivided cell assembly. Square shaped plates of platinum were used for working as well as counter electrode and a third electrode saturated calomel electrode was used as a reference electrode for the measurement of potential difference between two electrodes during the electrolysis.

scholarly journals Syntheses, Characterization and Biological Evaluation of a Series of 2-Phenylamino-5-(2-Chlorophenyl)-1,3,4-Oxadiazole Derivatives

2019 ◽  
Vol 18 (1) ◽  
pp. 75-83 ◽  
Author(s):  
S Kumar ◽  
PK Srivastava
Keyword(s):  
Room Temperature ◽  
Platinum Electrode ◽  
Saturated Calomel Electrode ◽  
Reference Electrode ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Platinum Electrodes ◽  
Mass Spectral ◽  
Elemental Analyses ◽  
Oxadiazole Derivatives

Electrochemical synthesis of 2-phenylamino-5-(2-chlorophenyl)-1,3,4-oxadiazoles have been carried out in good yields at platinum electrode through the electrochemical oxidation of acyl thiosemicarbazide at room temperature in acetic acid. Two platinum electrodes in the form of square plates were used as working as well as counter electrode and saturated calomel electrode was used as reference electrode. The structure of the compounds was confirmed by IR, NMR, mass spectral and elemental analyses. The antibacterial activity of the derivatives was also assessed and compared with data against a series of Gram-positive Klebsiella pneumoniae, Escherichia coli and Gramnegative bacteria Streptococcus aureus and Bascillus subtilis. The antifungal activity was assessed against the fungal strain Aspergillus niger, Crysosporium pannical, Pellicularia solmanicolor and Candida albicans and compared against the standard antifungal drug Griesvofulvin. Dhaka Univ. J. Pharm. Sci. 18(1): 75-83, 2019 (June)

scholarly journals Electro-organic Nuclear Oxidation: Methoxylation of Aromatic Compounds at Platinum Electrode

2011 ◽  
Vol 8 (2) ◽  
pp. 846-850 ◽  
Author(s):  
Sanjeev Kumar
Keyword(s):  
Aromatic Compounds ◽  
Supporting Electrolyte ◽  
Saturated Calomel Electrode ◽  
Analytical Data ◽  
Reference Electrode ◽  
Anodic Reaction ◽  
Controlled Potential Electrolysis ◽  
Electrode Cell ◽  
Controlled Potential ◽  
Good Agreement

The anodic oxidation of aromatic compounds was carried out at controlled potential in the non aqueous methanol-KOH system for the purpose of investigating this type of anodic reaction as a new possible synthetic method. The electroorganic nuclear oxidation was carried out at controlled potential electrolysis in a conventional three electrode cell assembly with platinum plate working as well as counter electrode and saturated calomel electrode as reference electrode. Controlled potential electrolysis was carried out in the solvent methanol and the supporting electrolyte in caustic potash. All the spectral and analytical data were found in good agreement with the synthesized compounds.

Study on Photo-Electro-Chemical Catalytic Degradation of Reactive Brilliant Red X-3B

2011 ◽  
Vol 213 ◽  
pp. 580-585
Author(s):  
Ming Yu Li ◽  
Kun Kun Wang ◽  
You Wu Su ◽  
Lin Song ◽  
Gang Cao ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Electrolyte Concentration ◽  
Supporting Electrolyte ◽  
Saturated Calomel Electrode ◽  
Reference Electrode ◽  
Catalytic Reactor ◽  
Solution Ph ◽  
Cathodic Potential ◽  
Pure Graphite ◽  
New Type

A new type of photo-electro-chemical catalytic reactor was designed. The cathode of the reactor was made of highly pure graphite and the anode was made of titanium dioxide. A saturated calomel electrode (SCE) was so used as the reference electrode that the electric potential of the cathode was determined. Under the condition of ultraviolet radiation and anodic bias-voltage, reactive brilliant red X-3B was degraded in the reactor synchronously by the process of photoelectrocatalysis with titanium dioxide anode and electrogenerated hydrogen peroxide through reducing dissolved oxygen with graphite cathode. With the cooperation of the cathode and the anode, impressive decolorizing efficiency of reactive red X-3B has been achieved. The results showed that, when the concentration of reactive brilliant red X-3B was 25mg••L-1 and the inert supporting electrolyte concentration was 0.005 mol•L-1 (1000mg•L-1) sodium sulfate, initial solution ph=4, and cathodic potential -Ec = 0.60 V, under UV radiation as well as constantly pumping air into the reactor, decolorizing efficiency of 79% has been achieved.

A new convenient synthesis of 5-aryl-2-(arylamino)-1,3,4-oxadiazole derivatives

2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Sanjeev Kumar
Keyword(s):  
Platinum Electrode ◽  
Electrical Energy ◽  
Reaction Rates ◽  
Cell Assembly ◽  
Undivided Cell ◽  
Controlled Potential Electrolysis ◽  
Convenient Synthesis ◽  
Controlled Potential ◽  
Oxadiazole Derivatives

AbstractElectrical energy offers numerous benefits for conducting a synthesis, including increased reaction rates, yield enhancements and cleaner chemistries. 5-Aryl-2-(arylamino)-1,3,4-oxadiazoles were synthesised directly from acylthiosemicarbazide on the platinum electrode under controlled potential electrolysis in an undivided cell assembly in acetonitrile.

Electrodeposition of Cu2O Particles by Using Electrolyte Solution Containing Glucopone as Surfactant

2009 ◽  
Vol 1 (2) ◽  
pp. 18-20
Author(s):  
Dahyunir Dahlan
Keyword(s):  
Indium Tin Oxide ◽  
Pulse Current ◽  
Platinum Electrode ◽  
Saturated Calomel Electrode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Continuous Current ◽  
Oxide Particles ◽  
Cupric Sulphate

Copper oxide particles were electrodeposited onto indium tin oxide (ITO) coated glass substrates. Electrodeposition was carried out in the electrolyte containing cupric sulphate, boric acid and glucopone. Both continuous and pulse currents methods were used in the process with platinum electrode, saturated calomel electrode (SCE) and ITO electrode as the counter, reference and working electrode respectively. The deposited particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that, using continuous current deposition, the deposited particles were mixture of Cu2O and CuO particles. By adding glucopone in the electrolyte, particles with spherical shapes were produced. Electrodeposition by using pulse current, uniform cubical shaped Cu2O particles were produced

Room Temperature Flow Electrochemistry as a Means of Retaining the “Memory of Chirality” via Hofer Moest Type Reaction

2020 ◽  
Author(s):  
Tomas Hardwick ◽  
Rossana Cicala ◽  
Nisar Ahmed
Keyword(s):  
Continuous Flow ◽  
Room Temperature ◽  
Biological Activities ◽  
Supporting Electrolyte ◽  
Enantiomeric Excess ◽  
Flow Chemistry ◽  
Batch Processes ◽  
Enabling Technology ◽  
Chiral Compounds ◽  
Memory Of Chirality

<p>Many chiral compounds have become of great interest to the pharmaceutical industry as they possess various biological activities. Concurrently, the concept of “memory of chirality” has been proven as a powerful tool in asymmetric synthesis, while flow chemistry has begun its rise as a new enabling technology to add to the ever increasing arsenal of techniques available to the modern day chemist. Here, we have employed a new simple electrochemical microreactor design to oxidise an L-proline derivative at room temperature in continuous flow. Flow performed in microreactors offers up a number of benefits allowing reactions to be performed in a more convenient and safer manner, and even allow electrochemical reactions to take place without a supporting electrolyte due to a very short interelectrode distance. By the comparison of electrochemical oxidations in batch and flow we have found that continuous flow is able to outperform its batch counterpart, producing a good yield (71%) and a better enantiomeric excess (64%) than batch with a 98% conversion. We have, therefore, provided evidence that continuous flow chemistry has the potential to act as a new enabling technology to replace some aspects of conventional batch processes. </p>

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.

Color and Antioxidant Changes in Various Natural Rubber Processes

2015 ◽  
Vol 754-755 ◽  
pp. 230-234 ◽  
Author(s):  
Suwimon Siriwong ◽  
Adisai Rungvichaniwat ◽  
Pairote Klinpituksa ◽  
Khalid Hamid Musa ◽  
Aminah Abdullah
Keyword(s):  
Acetic Acid ◽  
Natural Rubber ◽  
Retention Index ◽  
Total Phenolic Content ◽  
Room Temperature ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Lovibond Colorimeter

Fresh field natural rubber was coagulated by acetic acid, soaked in water at room temperature (WRT) or 70°C (W70) for 1 hr, and then dried in an oven at 40°C. Non-soaked natural rubber samples (NoW) served as a control. Two grades of natural rubber, namely air-dry sheet (ADS) and ribbed smoked sheet No.3 (RSS3) derived from the same latex, were also investigated. All dry rubber samples were characterized with Lovibond colorimeter according to ASTM D3157, as well as with a HunterLab spectrophotometer. Furthermore, all the dry rubber samples were dissolved in a chloroform:methanol mixture (4:1 v:v). The rubber was then precipitated out of the solution with methanol, and the remaining solution was quantitatively analyzed for total phenolic content (TPC). The plasticity retention index (PRI) was determined for all the dried rubber samples according to ASTM D3194. It was found that WRT, W70 and ADS were similar in lightness L*, while RSS3 had the lowest L*. W70 had the lowest redness a*, which increased in the order WRT, NoW, RSS3 and ADS. W70 also had the lowest yellowness b*, which increased in the order RSS3, NoW and WRT and ADS. Moreover, TPC was the lowest for the W70 sample, increasing in the order ADS, WRT, NoW and RSS3. The PRI was highest for W70, and decreased in the order WRT, RSS3, NoW and ADS. All of the PRI values observed were comparatively high relative to blocked standard Thai rubber 20 (STR20).

Fast Screening for Antioxidant Properties of Flavonoids from Pterogyne nitens Using Electrochemical Methods

2012 ◽  
Vol 95 (3) ◽  
pp. 773-777 ◽  
Author(s):  
Leonardo Luiz Okumura ◽  
Luis Octávio Regasini Regasini ◽  
Daniara Cristina Fernandes ◽  
Dulce Helena Siqueira da Silva ◽  
Maria Valnice Boldrin Zanoni ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Low Cost ◽  
Supporting Electrolyte ◽  
Antioxidant Properties ◽  
Reference Electrode ◽  
Structural Features ◽  
Quantitative Detection ◽  
Nonaqueous Media ◽  
Electrochemical Detector ◽  
Fast Screening

Abstract A fast, low-cost, convenient, and especially sensitive voltammetric screening approach for the study of the antioxidant properties of isoquercitrin and pedalitin from Pterogyne nitens is suggested in this work. These flavonoids were investigated for their redox properties using cyclic voltammetry in nonaqueous media using N,N-dimethylformamide and tetrabutylammonium tetrafluorborate as the supporting electrolyte, a glassy carbon working electrode, Ag|AgCl reference electrode, and Pt bare wire counter electrode. The comparative analysis of the activity of rutin has also been carried out. Moreover, combining HPLC with an electrochemical detector allowed qualitative and quantitative detection of micromolecules (e.g., isoquercitrin and pedalitin) that showed antioxidant activities. These results were then correlated to the inhibition of β-carotene bleaching determined by TLC autographic assay and to structural features of the flavonoids.

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

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