RESUMO
One of the multifactorial worldwide health syndromes is diabetes mellitus which is increasing at a disturbing rate. The inhibition of α-glucosidase, an enzyme that catalyzes starch hydrolysis in the intestine, is one helpful therapeutic approach for controlling hyperglycemia related to type-2 diabetes. To discover α-glucosidase inhibitors, some 2-hydrazolyl-4-thiazolidinone hybrids (3a-e) were synthesized from new one-pot reaction procedures. Next, their chemical structures were confirmed by 1H NMR, 13C NMR, and FT-IR spectra, and elemental analysis technique. Then, the α-glucosidase inhibitory activity of the titled compounds was evaluated. Among them, derivatives 3b and 3c revealed the highest activity against α-glucosidase compared to acarbose as a drug. Enzyme kinetic studies of the most active derivative (3b) indicated a competitive inhibition. Finally, molecular modeling studies were accomplished to describe vital interactions of the most potent compounds (3b and 3c) with the α-glucosidase enzyme.
RESUMO
In this study, a one-pot reaction between ß-keto esters or dialkyl acetylenedicarboxylates with hydrazines, carbon disulfide, and dialkyl acetylenedicarboxylates in the presence of triethylamine is reported. This reaction proceeded at room temperature and was completed within 6 h to produce functionalized pyrazolone-1,4-dithiafulvene hybrids in good yields.
RESUMO
A novel and efficient non-azo formation based method was developed for trace sensing of mesalazine (MES), a pharmaceutical aromatic amine. MES was simply coupled with a Meldrum's activated furan (MAF) reagent via a furan ring opening reaction to form a colored product. The intense purple colored solution was detected at 575 nm. The reaction of MES with MAF was monitored by employing 1H NMR spectroscopy and mass spectrometry. In addition, density functional theory (DFT) was applied to optimize the structure of the colored product and its λmax (the wavelength of maximum absorbance) in dimethyl sulfoxide and water. The colored product was considered in three possible structures, and the most possible structures in dimethyl sulfoxide and in water were identified by employing the DFT calculations. Both of the most possible structures indicated only a local excitation in their λmax and no charge transfer was observed. However, one of the structures in dimethyl sulfoxide presented charge transfer properties occurring through NCCC moiety. A univariate optimization method was also used to attain the optimum condition for analysis. In addition, the dependence of the analytical response on the three main affecting parameters (reaction time (X1), Triton X-100 concentration (X2) and MAF concentration (X3)) was identified by employing a central composite design (CCD) approach. The CCD study showed that the analytical response depends complexly on the parameters. Beer's law was obeyed within the range of 0.06-9.30 µg mL-1 of MES (155 fold linearity) at 575 nm, under the optimum condition introduced by the CCD approach. Also, the limit of detection was obtained 0.04 µg mL-1 of MES. The method showed precision (as relative standard deviation) and accuracy (as recovery) within the ranges of 0.6-3.2 % and 96.3-100.8%, respectively. Various organic and inorganic species, amino-pharmaceuticals, and amino acids were tested to evaluate the selectivity of the method. The selectivity of the analytical method was satisfactory. The method was successfully applied for detection of MES in various water matrices and pharmaceutical tablets.
Assuntos
Mesalamina , Micelas , Furanos , Comprimidos , ÁguaRESUMO
Four-component reaction between primary amines, dialkylacetylendicarboxylates, tetrazolo[1,5-a] quinoline-4-carbaldehyde and ethyl-2-cyanoacetate in the presence of 1,4-diaza-bicyclo[2.2.2]octane and zinc oxide nanoparticles results to the regioselective production of new tetrazolo[1,5-a]quinoline-based 2-amino-1,4-dihydropyridine or pyridin-2(1H)-one derivatives in good to high yields. The selectivity of the catalyzed reaction toward the generation of the dihydropyridine or pyridin-2(1H)-one derivatives was found to be strongly dependent on the size of the alkyl groups in the ester moieties of the acetylenic esters. According to single-crystal X-ray diffraction and NMR studies, the pyridin-2(1H)-one derivatives involve a restricted rotation around the C-C bond connecting the tetrazoloquinoline and dihydropyridinone cyclic systems.
Assuntos
Di-Hidropiridinas/química , Di-Hidropiridinas/síntese química , Nanoestruturas/química , Piridonas/química , Quinolinas/química , Tetrazóis/química , Óxido de Zinco/química , Catálise , Técnicas de Química Sintética , EstereoisomerismoRESUMO
One-pot solvent-free three-component reaction between primary amines, carbon disulfide, and 5-alkylidene rhodanines in the presence of a catalytic amount of tetra n-butylammonium bromide proceed at room temperature and produced asymmetric birhodanines in good to high yields within 5 min.
Assuntos
Aminas/química , Dissulfeto de Carbono/química , Rodanina/química , Catálise , Compostos de Amônio Quaternário/químicaRESUMO
AIM AND OBJECTIVE: Thiazol-2-imine derivatives are interested for their pharmaceutical and biologic activities. A literature survey reveals that there have been no any reports on the synthesis of thiazol-2-imine derivatives without substituents in position C-4 and C-5 via one-pot reaction. Herein we report an efficient one-pot route for synthesis of these compounds in good to high yields. MATERIALS AND METHOD: To a stirred mixture of amine (1 mmol) and phenylisothiocyanate (1 mmol) in EtOH (2 ml), KI (0.1 mmol) and DABCO (0.2 mmol) were added under reflux condition. Then α- chloroacetaldehyde (2 mmol) was added drop wise to the reaction mixture. After completion of the reaction, the product was purified over a silica gel short column (EtOAc/n-Hexane, 1:9). RESULTS: One pot reaction of primary amine, phenylisocyanate, and α-chloroacetaldehyde was carried out in the presence of various base and KI in different solvents. It was found that the maximum yield was obtained when the temperature reaches to the boiling point of EtOH. Comparing the reaction results in EtOH, CH3CN, THF, CH2Cl2, and H2O at reflux in the presence of various base, demonstrate that the yield of reaction in EtOH in the presence of DABCO was the most effective. When the reaction runs at the 20 mol% of the DABCO and 10 mol% of the KI, the yield and the time of the reaction were excellent. CONCLUSION: One-pot procedure can be used for the synthesis of thiazol-2-imine derivatives via the reaction of primary amines, α-chloroacetaldehyde, and phenylisothiocyanate in the presence of a catalytic amount of DABCO and potassium iodide in ethanol.
Assuntos
Acetaldeído/análogos & derivados , Técnicas de Química Combinatória/métodos , Iminas/síntese química , Isocianatos/química , Isotiocianatos/química , Tiazóis/síntese química , Acetaldeído/síntese química , Acetaldeído/química , Iminas/química , Isocianatos/síntese química , Isotiocianatos/síntese química , Estereoisomerismo , Tiazóis/química , Tioureia/análogos & derivados , Tioureia/síntese químicaRESUMO
An efficient, one-pot and three-component synthesis of biologically important heterocyclic compounds is described from the reaction of primary amines and phenyl isothiocyanate in the presence of acryloyl chloride at room temperature without the need to use any catalyst.
Assuntos
Acrilatos/química , Aminas/química , Isotiocianatos/química , Tiazinas/síntese química , Técnicas de Química Combinatória , Tiazinas/químicaRESUMO
One-pot reaction between enaminocarbonyl compounds derived from six-membered 1,3-diketones and substituted benzylamines, and electron-deficient acetylenic esters in the presence of triphenylphosphine lead to alkyl 2-(1-benzyl-6,6-dimethyl-2,4-dioxo-2,3,4,5,6,7-hexahydro-1H-indol-3-yl)acetate derivatives in good yields.
Assuntos
Acetatos/química , Acetatos/síntese química , Acetileno/química , Aminas/química , Indóis/química , Indóis/síntese química , Compostos Organofosforados/química , Técnicas de Química Sintética , ÉsteresRESUMO
The reaction of various primary amines with acetylenic esters at ambient temperature in THF/H(2)O (50:50) produced related enaminones. Subsequently reaction of these in situ prepared enaminones with dibenzoylacetylene leads to 3-alkylidene-2,3-dihydro-1H-pyrrol-2-ol derivatives in good yields. The reaction of these products with various alcohols in the presence of a catalytic amount of HCl produced highly functionalized pyrroles in nearly quantitative yields.
Assuntos
Técnicas de Química Combinatória/métodos , Pirróis/síntese químicaRESUMO
The reaction of dibenzoylacetylene and enaminocarbonyl compounds leads to 3-alkylidene-2,3-dihydro-1H-pyrrol-2-ol derivatives in nearly quantitative yields. The reaction of this heterocyclic system with alcohols in the presence of a catalytic amount of HCl produces highly functionalized pyrroles in good yields.
Assuntos
Pirróis/síntese química , Alquilação , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Pirróis/química , Espectrofotometria InfravermelhoRESUMO
The adduct produced in the reaction between tert-butyl isocyanide and dialkyl acetylenedicarboxylates was trapped by alkyl 2-arylamino-2-oxo-acetates. When the aryl group is 2-methyl-6-nitrophenyl or 2,6-di-isopropylphenyl, the product exists as two stable rotamers at room temperature as a result of restricted rotation around the Ar-N single bond. When the aryl group is 1-naphthyl or 8-quinolinyl, dynamic NMR effects are observed in the 1H NMR spectra. The calculated free-energy of activation for interconversion of the rotational isomers in 1-naphthyl and 8-quinolinyl derivatives amounts to about 99+/-2 and 68.5+/-2 kJ mol(-1), respectively.