- Catalytic synthesis of chloroacetates with thermoregulated ionic liquids based on vanadium-substituted polyoxometalate
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A series of polyoxometalate-based ionic liquid (POM-IL) catalysts with functional sulfonic acid groups, [TEAPS]3+nPW12-nVnO40 (n = 1, 2, 3) were synthesized and characterized by nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectrophotometry (FT-IR), UV-Vis spectrophotometry (UV), potentiometric titration and thermogravimetry-differential scanning calorimetry (TG-DSC). The catalytic ability and reusability of the POM-IL catalysts were evaluated on esterification of chloroacetic acid and n-amyl alcohol. The optimum reaction conditions, 0.2 g of the catalyst amount, 10 mL of water carrier, 140 °C of reaction temperature, and 1.2/1 of the molar ratio of alcohol/acid, were obtained by an orthogonal test. [TEAPS]5PW10V2O40 was found to be the best active catalyst with an esterification rate of 98.75% and could be reused five times without significant decrease in activity. The ionic liquid acted as a temperature-responsive catalyst, forming a homogeneous mixture with the reactants at reaction temperature, and could be precipitated and separated from products when the reaction ends at ambient temperature. Therefore, an environmentally friendly and highly efficient approach for the synthesis of chloroacetates is provided.
- Yan, Jingsen,Wang, Zeqing,Yongsheng,He, Fengwei,Zhang, Danfeng,Wu, Qingyin
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- Synthesis, in silico Study and Antimicrobial Evaluation of New Diesters Derived from Phthaloylglycine
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New diesters derived from phthaloylglycine (7a-7i) were synthesized and their structures characterized by infrared, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The compounds were evaluated in an in silico study, which demonstrated positive features indicating a possible drug candidate. The diesters showed antifungal activity ranging from moderate to strong against strains of Candida. Compounds 7a, 7b, 7c, 7e and 7i had a moderate minimum inhibitory concentration (MIC) of 1024 μg mL?1 against all fungal strains, while 7h showed a very good MIC of 256 μg mL?1 against Candida albicans, Candida parapsilosis and Candida krusei and 64 μg mL?1 against Candida tropicalis. However, only 7h and 7i were able to inhibit bacterial growth of strains of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Escherichia coli with an MIC of 1024 μg mL?1
- Alves, Francinara S.,Barbosa-Filho, José M.,Cordeiro, Laísa V.,Huang, Min-Fu N.,Lima, Edeltrudes O.,Neto, Hermes Diniz,Souza, Helivaldo D. S.,Trindade, Emmely O.,de Athayde-Filho, Petr?nio F.,de Lima, Priscila S. V.,de Oliveira, Rafael F.,de Sousa, Abra?o P.
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p. 953 - 962
(2020/10/14)
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- New Diesters Derived from Piperine: In silico Study and Evaluation of Their Antimicrobial Potential
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Piperine, previously extracted from black pepper (Piper nigrum L.), was used as a precursor for the synthesis of twelve new diester derivatives. The final products were obtained through the bimolecular nucleophilic substitution reaction (SN2) of the alkyl 2-chloroacetates and the salt of piperic acid, obtained from the basic hydrolysis of piperine. The compounds were synthesized with yields of 55-84% and characterized by infrared spectroscopy and 1H and 13C nuclear magnetic resonance. The evaluation of the compounds’ potential as new drug candidates was done through an in silico study of ADME properties (absorption, distribution, metabolization and excretion) and evaluation of antimicrobial activity against bacterial strains (Staphylococcus aureus and Pseudomonas aeruginosa), yeasts (Candida albicans and Candida tropicalis) and filamentous fungi (Aspergillus fumigatus, Aspergillus flavus and Aspergillus niger). The in silico study showed that the compounds were good drug candidates and antimicrobial evaluation demonstrated that 9 of the 12 compounds exhibited a minimum inhibitory concentration (MIC) ranging 1024-256 μg mL?1
- Barbosa-Filho, José M.,Brand?o, Maria Cláudia R.,Lima, Edeltrudes O.,Lira, Bruno F.,Neto, Hermes D.,Souza, Helivaldo D. S.,Trindade, Emmely O.,de Athayde-Filho, Petr?nio F.
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p. 1668 - 1678
(2020/10/09)
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- Preparation method of novel thermosensitive ionic liquid and method for synthesizing chloracetate catalytically
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The invention discloses an acid functionalized-temperature controlled ternary heteropolyacid ionic liquid and a preparation method thereof, as well as an esterification method for synthesizing chloracetate catalytically. The structural formula of the heteropolyacid ionic liquid is as shown in a formula (I). The ionic liquid has a temperature responding characteristic during esterification reactionof chloroacetic acid and chloroacetic acid, is mixed with a reactant as one phase at the reaction temperature, and is further divided into two phases with the product when the temperature is reducedto a room temperature after the reaction. A catalyst and a reaction product can be separated quickly by simple filtration. The ionic liquid not only has the advantages of being convenient to recover and free of waste acid emission, but also has the characteristics of being high in esterification efficiency, good in repeated using performance and the like.
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Paragraph 0023-0026; 0032
(2019/04/02)
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