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61.
Three anti-microbial pharmaceutical drugs were synthesized from two different synthetic routes. 4-acrylamido-N-(5-methyl-3-isoxazolyl)benzenesulfonamide (AMBS) and 4-methacrylamido-N-(5-methyl-3-isoxazolyl)benzenesulfonamide (MMBS) were prepared by reacting acryloyl chloride and methacryloyl chloride with 4-amino-N-(5-methyl-3-isoxazolyl)benzenesulfonamide in the presence of triethylamine. N-[4-sulfamido-N-(5-methyl-3-isoxazolyl)phenyl]maleimide (SMPM) was prepared by reacting maleic anhydride with 4-amino-N-(5-methyl-3-isoxazolyl)benzenesulfanamide. These monomers (AMBS, MMBS and SMPM) were polymerized using BPO as a free radical initiator. The pharmacological activity of SMPM compound depends on the functional group in the structure and small structural changes has resulted in higher pharmacological activity of sulfamethoxazole. Thus, maleimide polymer drug conjugate showed greater anti-microbial activity when compared with that of the native drug. 相似文献
62.
本文定义了一个新的代数系{R×C×S}这是一个有环结构的自由R-模,并讨论了结构性质与R的性质. 相似文献
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The electrochemical oxidation of 3,4-ethylenedioxythiophene (EDOT) on platinum is studied in electrolyte solutions containing hydroxypropyl-β-cyclodextrin (HP-β-CD). HP-β-CD is found to increase the solubility of EDOT up to a concentration of 0.026 M in aqueous solutions. Addition of HP-β-CD (0.1 M) produces a slight red shift of the EDOT main absorption band from 254.9 to 257.7 nm and an increase of the HP-β-CD concentration decreases the absorption coefficient, max to 6150 l mol−1 cm−1 in the UV–vis region, indicating complex formation. The cyclic voltammetric response of EDOT in 0.1 M aqueous LiClO4 solutions consists of an ill-defined wave (P1) and an adsorption peak (P2). Contrary to the case of oxidation in acetonitrile medium, a post-peak is observed in the voltammograms of EDOT electro-oxidation in aqueous LiClO4 solutions due to the adsorption of the oxidized EDOT species. A gradual reduction of the peak current of P2 with increasing [HP-β-CD] and its total disappearance at high [HP-β-CD] suggest complex formation between HP-β-CD and EDOT√+ and also the peak P2 to be due to adsorption of EDOT√+ species. The experiments intended to show the effect of ‘pre-adsorbed’ HP-β-CD on EDOT oxidation led to the conclusion that adsorbed HP-β-CD also solubilizes EDOT at the electrode surface. The CV behaviour of EDOT in HP-β-CD is discussed in comparison with that in sodium dodecylsulfate micellar solutions. Addition of increasing amounts of HP-β-CD shifts P1 positively and P2 negatively while also suppressing P2 totally and reducing the peak current of P1 to a significant extent. At a higher concentration of HP-β-CD, viz. 0.05 M, a peak appears at 1.29 V as a result of the above two opposing effects of CD on the peak potentials of P1 and P2. This resultant peak (Pcomposite) is more positive relative to the position of P1 observed in the absence of HP-β-CD. The positive shift of the peak and peak current reduction indicate that EDOT (or an oxidized EDOT species) possibly interacts with the outer nucleophilic part of HP-β-CD. The electro-oxidation processes occurring at P1 and P2 are explained using an oligomeric approach, in which the electrochemical reactions are coupled to chemical reactions or adsorption of the oxidized species. Potential cycling of the platinum electrode in solutions containing 0.026 M EDOT+0.05 M HP-β-CD+0.1 M LiClO4 between −0.5 and 1.2 V yields an adherent and smooth polymer film of poly(ethylenedioxythiophene), as shown in the SEM examination. In situ resistance measurements carried out with the polymer films in the electroactive region show a minimum resistance in the potential range of 0.3–0.4 V. Even the electrochemically-reduced films are found to possess some residual electrical conductivity. 相似文献
66.
The first total synthesis of (±)-lagopodin A and a formal total synthesis of enokipodins A and B is described. The requisite precursors containing two vicinal quaternary carbon atoms were assembled employing Claisen rearrangement and an RCM reaction as key steps starting from 2,5-dimethoxy-4-methylacetophenone. 相似文献
67.
S. Viveka G. Vasantha Dinesha S. Naveen N. K. Lokanath 《Molecular Crystals and Liquid Crystals》2016,629(1):135-145
The present study describes the synthesis, spectroscopic, and single crystal X-ray structural analysis of ethyl 5-methyl-1-phenyl-1H-pyrazole-4-carboxylate. The pyrazole ester of formula [C13H14N2O2] was prepared from the three-component one-pot condensation reaction of ethyl acetoacetate, N,N-dimethyldimethoxymethanamine, and phenyl hydrazine. The product was crystallized by using ethanol as solvent. The structure of the compound was confirmed by elemental analysis, Fourier transforms infrared (IR), thermogravimetric analysis, UV-visible (UV-Vis), 1H NMR, and single-crystal X-ray diffraction studies. The gas-phase molecular geometry and the electronic structure-property of the molecule were calculated at the density functional theory. The frontier molecular orbitals, theoretical UV-Vis, and IR stretching vibrations were also reported. The compound crystallizes in the monoclinic system with the space group P21/c and Z = 4. The unit cell parameters are a = 12.141(3) Å, b = 13.934(4) Å, c = 7.2777(18) Å, and β = 97.816(14)0. The structure is stabilized by an intermolecular interaction of type C-H···O and the structure also involves C-H···π interactions. 相似文献
68.
Bhat Mahima Gurubasavaraja Swamy P. M. Poojary Boja Revanasiddappa B. C. Vijay Kumar M. Kumar Vasantha 《Research on Chemical Intermediates》2018,44(4):2779-2805
Research on Chemical Intermediates - A new series of hybridized thiazol-2-yl-hydrazone derivatives having diverse substituents were designed, synthesized, and screened for their anti-inflammatory... 相似文献
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Viveka Shivapura Vasantha Gowda Dinesha Naveen Shivalingegowda Lokanath Neratur Krishnappagowda Nagaraja Gundibasappa Karikannar 《Research on Chemical Intermediates》2016,42(5):4497-4511
Research on Chemical Intermediates - The present research work has focused on combined experimental and theoretical studies of one of the biologically important pyrazole-4-carboxylic acid... 相似文献