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A Study of the Kinetic and Mechanism of Oxidation of Pyrazole Derivative by Permanganate Ion in Neutral Medium and the Effect of Metal Ion Catalysts
Ismail Althagafi,
Ahmed Fawzy
Issue:
Volume 2, Issue 1, December 2016
Pages:
1-7
Received:
16 September 2016
Accepted:
31 October 2016
Published:
21 November 2016
DOI:
10.11648/j.ajhc.20160201.11
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Abstract: Oxidation of methylaminopyrazole formamidine (MAPF) by permanganate ion was studied spectrophotometrically in neutral medium in the presence of phosphate buffer solution. The stoichiometry of the reaction was found to be 3: 2 (MAPF: MnO 4-). The oxidation reaction showed a first order kinetics with respect to [MnO4-] and a fractional-first order dependence with respect to [MAPF]. Addition of small amounts of some metal ions increased the oxidation rate and the order of catalytic efficiency was: Ag(I) > Cu(II) > Al(III). The suggested oxidation mechanism involves formation of a 1:1 intermediate complex between permanganate ion and MAPF. The formed complex decomposes in the rate-determining step to yield a free radical derived from MAPF and an intermediate Mn(VI). The free radical is attacked by Mn(VI) species to give rise to the final oxidation products which were identified by both spectroscopic and chemical tools as methylaminopyrazole, dimethylamine and carbon dioxide. The rate-law expression was deduced and the reaction constants involved in the different steps of the suggested mechanism were evaluated. The activation parameters of the rate constant of the slow step along with the thermodynamic quantities of the formation constant of the intermediate complex were evaluated and discussed.
Abstract: Oxidation of methylaminopyrazole formamidine (MAPF) by permanganate ion was studied spectrophotometrically in neutral medium in the presence of phosphate buffer solution. The stoichiometry of the reaction was found to be 3: 2 (MAPF: MnO 4-). The oxidation reaction showed a first order kinetics with respect to [MnO4-] and a fractional-first order de...
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Spectroscopic Identification and Synthesis of Derivatives of Pyrimidine 2- Thione Via Two Different Spacers
Moayed J. Mohammed,
Ahmed Kh. Ahmed,
Faris T. Abachi
Issue:
Volume 2, Issue 1, December 2016
Pages:
8-12
Received:
28 October 2016
Accepted:
12 November 2016
Published:
10 December 2016
DOI:
10.11648/j.ajhc.20160201.12
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Abstract: A new series of pyrimidine -2-thione derivatives were synthesized via two routes and designated as antifolate. The heterocyclic ring was prepared by direct reaction of benzoyl acetone with thiosemicarbiazide in acidic medium. Also, the pyrimidine-2-thione ring reacts with p-aminobenzoic acid to form 4-amino-N-(4-methyl-6-phenyl)-2-thioxypyrimidine 1[2H] –yl benzamide. The second route synthesis 5-[{4-methyl-6-phenyl-2-thioxo pyridine-1-yl amino}-4-(4-methyl phenylsulfonamido)-5-oxobenzoyl] pentanoic acid. All structures were elucidate by their physical & spectroscopic data FTIR, 1H &13C NMR.
Abstract: A new series of pyrimidine -2-thione derivatives were synthesized via two routes and designated as antifolate. The heterocyclic ring was prepared by direct reaction of benzoyl acetone with thiosemicarbiazide in acidic medium. Also, the pyrimidine-2-thione ring reacts with p-aminobenzoic acid to form 4-amino-N-(4-methyl-6-phenyl)-2-thioxypyrimidine ...
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Aqueous Synthesis and Biological Studies of Indole Derivatives
Sudhakara Aralihalli,
Raghavendra Ramappa,
Harish Basavanthappa Gowdru,
Nataraja Gummanar,
Ramesha Sonnappa,
Mahadevan Kittappa Malavalli
Issue:
Volume 2, Issue 1, December 2016
Pages:
13-19
Received:
26 October 2016
Accepted:
12 November 2016
Published:
27 December 2016
DOI:
10.11648/j.ajhc.20160201.13
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Abstract: One pot with expedient approach to the synthesis of 2,3-disubstituted indole derivatives using indium (III) trichloride through Fisher indole method has been developed, in aqueous media. The synthesized compounds were screened for their anti analgesic and antibacterial activity. All the six indole derivatives exhibited significant antibacterial activity against Pseudomonas aeruginosa when compared to standard drug Ciprofloxacin. Based on the results of antibacterial activity, the molecular docking of all six indole derivatives were performed against Pseudomonas elastase a matrix metalloproteinase from Pseudomonas aeruginosa were presumed as an infectious wound healer via MMP dependent pathway. The active pocket docked with indole derivatives at the torsional degree of freedom 0.5 units with Lamarckian genetic algorithm. The inhibitors binding is facilitated by direct hydrogen bond interactions with the residues residing in the catalytic motif of Pseudomonas elastase consisted of Ala113, His140, Glu141, His144, Glu164, Arg198 and His223. In addition, the inhibitors make many hydrophobic interactions with both the enzyme and the co-factor Zinc ion. In view of the possibility that the elastase is an important determinant in Pseudomonas infection, it is conceivable that inhibitors of the enzyme will reduce its destructive effects that may lead to new therapeutic intervention.
Abstract: One pot with expedient approach to the synthesis of 2,3-disubstituted indole derivatives using indium (III) trichloride through Fisher indole method has been developed, in aqueous media. The synthesized compounds were screened for their anti analgesic and antibacterial activity. All the six indole derivatives exhibited significant antibacterial act...
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Aqueous Polyurethane Dispersions - Sodium Alginate Based Blends and Hydrogels
Tamara Travinskaya,
Yuri Savelyev
Issue:
Volume 2, Issue 1, December 2016
Pages:
20-25
Received:
28 October 2016
Accepted:
24 November 2016
Published:
5 January 2017
DOI:
10.11648/j.ajhc.20160201.14
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Abstract: The film forming binary polyurethane-alginate blends and based hydrogels, containing different alginate content, were prepared by blending of anionic polyurethane dispersions (APD) and aqueous sodium alginate (SA) solution. Binary blends of APD and SA were cast in film form from mixed aqueous polymer solutions by solvent evaporation. Post-treatment of as-cast films with CaCl2 leaded tot he hydrogels formation. The thermal stability, thermal transition, water-swelling, mechanical properties and gas permeance for O2 and CO2 of two kinds of films were examined according to alginate content. Irrespective of composition, blend samples gave a single glass transition temperature (Tg), indicating the formation of thermodynamically miscible phase. The shift of Tg in hydrogels to the higher temperatures indicated the possible simultaneous occurrence of a chelate complexation of SA with Ca+2 cations, cross-links between polyurethane chains, having carboxylate anions, with Ca2+ cations, and interactions between SA and anionic polyurethane, resulting in the formation of an semi-interpenetrating network structure. The relationships between the films structure, their physicochemical properties and alginate content have been discussed.
Abstract: The film forming binary polyurethane-alginate blends and based hydrogels, containing different alginate content, were prepared by blending of anionic polyurethane dispersions (APD) and aqueous sodium alginate (SA) solution. Binary blends of APD and SA were cast in film form from mixed aqueous polymer solutions by solvent evaporation. Post-treatment...
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Synthesis and Characterization of New Complex Heterocyclic Ring Systems of Industrial Importance
Ayuk Eugene Lakem,
Nweke Cletus Mgadiugha,
Ugwu Marigoretti Ogechukwu
Issue:
Volume 2, Issue 1, December 2016
Pages:
26-31
Received:
12 July 2016
Accepted:
19 December 2016
Published:
10 January 2017
DOI:
10.11648/j.ajhc.20160201.15
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Abstract: The synthesis and characterization of new complex monoaza and pentaaza angular phenothiazine derivatives is reported. The first derivative, 6,10-dichloro-17-azadibenzo[a,n]triphenodithiazin-5,11-dione 10 was obtained by a base-catalyzed reaction of 2,6-diaminopyridine-3,5-dithiol 5 and 2,3-dichloro-1,4-naphthaquinone 9, while the second derivative, 7,9,15,17-tetraamino-6,8,16,18,25-pentazadibenzo[a,n]di([1,4]benzothaizino[3,2-c,l])triphenodiathizine 11 was obtained by the reaction of two moles of 2, 4, 6-triaminopyrimidine-3-thiol 8 and one mole of compound 10 under the same reaction conditions. The assigned structures to the above synthesized compounds were done on the basis of spectroscopic analysis.
Abstract: The synthesis and characterization of new complex monoaza and pentaaza angular phenothiazine derivatives is reported. The first derivative, 6,10-dichloro-17-azadibenzo[a,n]triphenodithiazin-5,11-dione 10 was obtained by a base-catalyzed reaction of 2,6-diaminopyridine-3,5-dithiol 5 and 2,3-dichloro-1,4-naphthaquinone 9, while the second derivative,...
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Synthesis of Some New N-[1-(Benzocoumarin-3`-yl)Ethylidene]Hydrazonothiazolidine, Thiazole and 1, 3, 4-Thidiazole Derivatives
Hussein A. Emam,
Saber M. Hassan,
Ahmed M. El-Agrody,
Ahmed H. Bedair,
Mahmoud M. Abdelall
Issue:
Volume 2, Issue 1, December 2016
Pages:
32-38
Received:
10 December 2016
Accepted:
22 December 2016
Published:
12 January 2017
DOI:
10.11648/j.ajhc.20160201.16
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Abstract: Condensation of 3-acetylbenzo[5,6]coumarin (1) with hydrazine-carbodithioate esters and/or thiocarbohydrazide gave the corresponding N-[1-(benzocoumarin-3`-yl)ethylidene]hydrazonecarbodithioate (2a,b) and 1,5-bis[1-(benzocoumarin-3`-yl)ethylidene]thiocarbohydrazide (3) respectively. Treatment of 2a with ethanolic ammonia solution and/or amines gave the corresponding thiosemicarbazone derivatives (4a-f). The reactions of 4a-f with ethyl bromoacetate/AcONa and ω-bromo derivatives were investigated, where thiazolidinones 5, 6 and thiazoles (9a,b) were obtained. Moreover, hydrazonecarbodithioate (2) underwent heterocycliczation upon treatment with hydrazonoyl halides (10) with Et3N to give the corresponding 2,3-dihydro-1,3,4-thiadiazoles (11a-d) via 1,3-dipolar cycloaddition and/or nuclophilic substiution. The structures of the new derivatives were elucidated by elemental analysis, IR, PMR and mass spectra.
Abstract: Condensation of 3-acetylbenzo[5,6]coumarin (1) with hydrazine-carbodithioate esters and/or thiocarbohydrazide gave the corresponding N-[1-(benzocoumarin-3`-yl)ethylidene]hydrazonecarbodithioate (2a,b) and 1,5-bis[1-(benzocoumarin-3`-yl)ethylidene]thiocarbohydrazide (3) respectively. Treatment of 2a with ethanolic ammonia solution and/or amines gave...
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