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61.
Dattatraya K. Jamale Santosh S. Undare Navanath J. Valekar Aniket P. Sarkate Govind B. Kolekar Prashant V. Anbhule 《Journal of heterocyclic chemistry》2019,56(2):608-618
A series of 4‐(1H‐pyrazol‐4‐yl)‐polyhydroquinolines were synthesized through one‐pot four‐component Hantzsch condensation of 1,3‐diphenyl‐1H‐pyrazole‐4‐carbaldehydes, ammonium acetate, dimedone, and alkyl acetoacetate in glycerol as a green reaction medium. The structures of the compounds are verified by spectroscopic methods and screened for their antimicrobial activity against Mycobacterium tuberculosis H37RV strain. Almost all the synthesized derivatives reveal excellent antitubercular activity based on minimum inhibitory concentration. Especially the compounds 5h and 5k exhibit outstanding antitubercular activity with minimum inhibitory concentration 1.6 μg/mL. In addition, molecular docking study of synthesized scaffolds against enoyl‐acyl carrier protein reductase from M. tuberculosis was performed to propose the binding modes. 相似文献
62.
Solvent extraction separation method for the determination of rhodium(III) has been described. Selective and quantitative extraction of rhodium(III) by N-n-octylaniline, a high molecular weight amine (HMWA) into xylene takes place from aqueous sodium malonate medium. The effect of concentration of malonate, N-n-octylaniline, role of various diluents, stripping agents and foreign ions on the extraction of rhodium(III) has been studied. The procedure offers distinct improvements in need of real sample analysis and environmental safety as the extraction procedure carried out in weak organic acid media. 相似文献
63.
Sequence Selective Michael Addition for Synthesis of Indeno‐Pyridine and Indeno‐Pyran Derivatives in One‐Pot Reaction Using CuO Nanoparticles in Water 下载免费PDF全文
Navanath J. Valekar Prasad P. Patil Anil H. Gore Govind B. Kolekar Madhukar B. Deshmukh Prashant V. Anbhule 《Journal of heterocyclic chemistry》2015,52(6):1669-1676
The alternate synthesis of indeno‐pyridine and indeno‐pyran derivatives have been described by an unprecedented, green, one‐pot reaction of aromatic aldehydes, malononitrile, and indane 1,3‐dione. The formation of either indeno‐pyridine or indeno‐pyran derivatives based on a precise change in the Michael addition of indane 1,3‐dione or malononitrile on Knoevenagel product during the progress of reaction has been investigated. The reaction completed up to 30 min of time using CuO nanoparticles in water at an ambient temperature renders the protocol novel and environment friendly. All the synthesized compounds have been confirmed on the basis of their spectroscopic data. The CuO nanoparticles have been prepared by coprecipitation method and characterized by SEM, PXRD spectroscopy, and UV spectroscopy. 相似文献
64.
Biswajit Sadhu Mahesh Sundararajan Anilkumar Pillai Rajvir Singh Tusar Bandyopadhyay 《International journal of quantum chemistry》2017,117(22)
Selective extraction of a radionuclide in the presence of other interfering ions is one of the vital steps in the back‐end‐of‐the‐nuclear fuel cycle. The presence of interfering cations (such as Ca2+) in the radioactive waste and involvement of multiple separation steps are known to be bottlenecks in the efficient Sr2+ extraction. Here, using free energy corrected density functional theory, we have proposed a two‐step Sr2+ extraction methodology in nitrate media in the presence of interfering Ca2+ ion using a multitopic ion‐pair receptor, which was earlier reported to be strongly selective for K+ (Kim et al. J. Am. Chem. Soc. 2012, 134 , 1782–1792). To depict the correct free energy trend in the proposed extraction processes, the most probable binding mode of the metal (Sr2+, Ca2+, and K+) nitrates in the host are identified. In excellent agreement with the previously reported experiment, Crown/Pyrrole (C/P) binding is noted to be the most preferable mode for KNO3, where K+ and occupied the Crown (C) and Pyrrole (P) site, respectively. However, the divalent metal ions (Ca2+ and Sr2+) are noted to marginally prefer Crown/Crown‐Pyrrole (C/CP) mode, in which metal reside at the C site while two nitrates occupy the P site and also simultaneously bind at the outer sphere of C site to coordinate with the metal via monodentate motif. Based on the free energy of extraction, we predict that the selective separation of chemically alike Ca2+/Sr2+ pair is indeed achievable using this receptor. We propose that once [Sr(NO3)2] is extracted in organic media, the receptor's high affinity toward K+ in nitrate media can be used to back strip Sr2+ to the aqueous phase. 相似文献
65.
Kirti T. Patil Dattatrya K. Jamale Navnath J. Valekar Priyanka T. Patil Poojali P. Warekar Govind B. Kolekar 《合成通讯》2017,47(2):111-120
Fused pyrazolopyranopyrimidines containing both biologically active pyranopyrazole and pyranopyrimidine compounds were synthesized using a one-pot, four-component reaction of ethyl aceto acetate, hydrazine hydrate, benzaldehydes, and thiobarbituric acid without catalyst in ethanol. All target compounds obtained in very good to excellent yields over short reaction times by adapting a simple workup procedure. All the synthesized compounds exhibited good to excellent antituberculosis activities. The results shown that 4-(1H-imidazol-2-yl)-3-methyl-7-thioxo-4,6,7,8-tetrahydropyrazolo[4’,3′:5,6]pyrano[2,3-d] pyrimidin-5(1H)-one (5a) is a good antitubercular agent, as good as the standard streptomycin drug, based on minimum inhibitory concentration (MIC). 相似文献
66.
Studies on matrix interferences during uranium analysis by extractive liquid scintillation technique
Reddy Priyanka J. Pulhani Vandana Dhole S. D. Dahiwale S. S. Bhade S. P. D. Kolekar R. V. Anilkumar S. Singh Rajvir 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(3):1923-1927
Journal of Radioanalytical and Nuclear Chemistry - The efficiency of ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) in reducing the influence of salinity and... 相似文献
67.
68.
S.K. Kolekar 《Applied Surface Science》2011,257(23):10306-10310
Thermionic emission from vertically grown carbon nanotubes (CNTs) by water-assisted chemical vapor deposition (WA-CVD) is investigated. I-V characteristics of WA-CNT samples exhibit strong Schottky effect leading to field proportionality factor β ∼ 104 cm−1in contrast to β ∼ 200 cm−1 for the bare tungsten substrate. Non-contact atomic force microscopy imaging of CNT samples show propensity of nanoasperities over a scale of micron size over which the tungsten surface is seen to be atomically smooth. The values of root mean-square roughness for CNTs and W were found to be 24.2 nm and 0.44 nm respectively. The Richardson-Dushman plots yield work function values of ΦCNT ? 4.5 and ΦW ? 4.3 eV. Current versus time data shows that CNT cathodes are fifteen times noisier than tungsten cathode presumably due to increased importance of individual atomic events on the sharp CNT tips of bristle like structures. Power spectral density of current exhibited 1/fξ behavior with ξ ? 1.5, and 2 for W and CNTs. The former suggests surface diffusion whereas the latter indicates adsorption/desorption of atomic/molecular species as a dominant mechanism of noise generation. 相似文献
69.
A novel method for the quantitative determination of ranitidine hydrochloride (RNH) based on the fluorescence quenching of functionalised CdS quantum dots (QDs) by RNH in aqueous solution was proposed. The method is simple, rapid, specific and highly sensitive with good precision. The thioglycolic acid (TGA)-capped CdS QDs were synthesized from cadmium nitrate and sodium sulfide in alkaline solution. Under the optimal conditions, the Stern-Volmer calibration plot of F(0)/F against concentration of RNH was linear in the range of 0.50-15.0 μg mL(-1) with a correlation coefficient of 0.996. The limit of detection (LOD) was 0.38 μg mL(-1). The method was satisfactorily applied to the direct determination of RNH in pharmaceutical formulations with no significant interference from excipients. The results were found to be in good agreement with those obtained by the reference method and the claimed value. The accuracy and reliability of the method were further ascertained by recovery studies via the standard-addition method, with percentage recoveries in the range of 98.47 to 102.30%. The possible fluorescence quenching mechanism for the reaction was also discussed. 相似文献
70.
A fluorimetric method based on fluorescence enhancement effect was developed for the determination of adenosine 5′-monophosphate
(AMP) with 9-anthracene carboxylic acid (9-ANCA)–cetyl trimethyl ammonium bromide (CTAB) system. Fluorescence intensity of
9-ANCA was decreased by the addition of CTAB but addition of AMP again rose the intensity of 9-ANCA gradually. The observed
fluorescence enhancement is attributed to the competitive binding reaction of 9-ANCA and adenosine to CTAB. The enhancement
in the fluorescence intensity was found proportional to the concentration of AMP over the range 2.0 × 10−4 to 1.2 × 10−3 mol dm−3. The ion pair complex is formed spontaneously between 9-ANCA and CTAB. Since the binding interaction is larger for the adenosine–CTAB
pair, the fluorophore 9-ANCA will be released. The quantum yield of free 9-ANCA is higher therefore its fluorescence observed
at 417 nm wavelength is enhanced. This mechanism of competitive molecular interaction is further confirmed by conductometric
measurements. The method was applied successfully for the determination of AMP from pharmaceutical sample. The method is more
selective, sensitive and relatively free from interferences. 相似文献