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51.
Iodine–ammonium acetate–mediated annealation of dimedone with aldehydes led to facile formation of spirodihydrofuran in good yields through tandem Knoevenagel–Michael iodonation and cyclodehydroiodonation reactions in a single pot. 相似文献
52.
Aneeta Kharkwal Kiran Jain S. B. Tyagi A. K. Singh Shailesh N. Sharma Mamta Kharkwal 《Colloid and polymer science》2014,292(11):2913-2926
The single-pot synthesis of highly crystalline and fluorescent chalcopyrite CuInS2 (CIS) colloidal nanoparticles has been reported by thermal decomposition of metal ethyl xanthate (at ~110 °C) for the first time. The fluorescence emission wavelength can also be readily tuned from the UV to the visible region by merely prolonging the reaction time, as the PL emission may be varied from 550 to 675 nm. The synthesized CIS is subjected to postdeposition treatment with CdS/ZnS in one pot route using cadmium/zinc xanthate at low temperature (~80 °C) to improve the quantum yield of core–shell (CIS/CdS or ZnS) nanocrystallites as compared to CIS core. The stability of core–shell particularly CIS/ZnS system upon continuous laser exposure suggests the formation of surface bonds with superior mechanical stability. This low-cost synthesis of such nontoxic QDs using green chemical routes is a promising approach for the fabrication of optoelectronic and biosensing devices. Graphical Abstract
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53.
Shailesh Thakrar Abhay Bavishi Ashish Radadiya Shrey Parekh Dhairya Bhavsar Hardevsinh Vala Nilay Pandya Anamik Shah 《Journal of heterocyclic chemistry》2013,50(Z1):E73-E79
A new series of highly functionalized 1,5‐benzodiazepine derivatives 5a–x have been synthesized from 3‐[(1E)‐N‐(2‐aminophenyl) ethanimidoyl]‐4‐hydroxyl‐2H‐chromen‐2‐one 3a–c and pyrazole aldehyde 4a–h using catalytic amount of triflouro acetic acid under microwave irradiation. The main significant of the present procedure is shorter reaction time, easy work up procedure, and excellent yield with high purity. The structures of all the compounds were established on the basis of their IR, NMR, and mass spectral data and have been screened for their antimicrobial activity and antifungal activity. 相似文献
54.
The reaction between ozone and carbon monoxide was reinvestigated in the range of 80–160°C. The previously reported rate law ?d[O3]/dt = ka[O3][CO] + kb[O3]2 was confirmed and simulated using a mechanism based on an impurity-initiated chain reaction. When the CO was sufficiently purified, kb tended to zero and ka reduced to the value expected for the thermal decomposition of O3. Subsequent reactions of O atoms with CO produced chemiluminescence which was used to measure k3 for as 10?14.0±0.3 exp[?(1630 ± 325)/T] cm3 molecule?1 s?1. The implications of this are discussed. 相似文献
55.
Pintu Prajapati Veera Shakar Pulusu Shailesh Shah 《Journal of separation science》2023,46(11):2300139
White analytical chemistry is a novel concept for the assessment of analytical methods on basis of its validation efficiency, greenness power, and economical efficiency. White analytical chemistry-driven stability indicating chromatographic method has been developed for the concomitant analysis of thiocolchicoside and aceclofenac. The proposed chromatographic method has been developed using a safe and environmental-friendly organic solvents for the concomitant stability study of thiocolchicoside and aceclofenac. The analytical risk assessment was carried out for the identification of high-risk analytical risk factors and analytical method performance attributes. The mixture design was applied for the design of experiments-based response surface modeling of high-risk analytical risk factors and analytical method performance attributes. The degradation products were isolated and characterized using infrared, nuclear magnetic resonance, and mass spectral data. The proposed method was compared for its validation efficiency, greenness power, and cost-efficiency with published chromatographic methods using the red, green, and blue models. The white score of the proposed and reported method was calculated by averaging the red, green, and blue scores of the methods. The proposed method was found to be robust, green, and economical for the concomitant stability study of thiocolchicoside and aceclofenac. 相似文献
56.
Anil Bhatia Baleshwar Meena Sanjeev K. Shukla Dalip K. Upreti Anuradha Mishra 《Analytical letters》2017,50(1):233-242
A rapid and reliable method was developed and validated for determining betulin and betulinic acid in bark in Betula utilis by high-resolution magic angle spinning 1H nuclear magnetic resonance (HR-MAS NMR) spectroscopy. HR-MAS NMR spectroscopy clearly distinguished the resonances of betulin and betulinic acid in the bark of all accessions of B. utilis. The concentrations of betulin and betulinic acid were calculated and added to the spectra. The determination of the targeted metabolites in chloroform extract of bark of each accession of B. utilis was performed by high-performance liquid chromatography (HPLC). Quantitatively, betulin was present at higher concentrations than betulinic acid in all accessions. The HR-MAS NMR and HPLC results showed that betulin and betulinic acid varied significantly among accessions of B. utilis. Principal component analysis of the NMR and HPLC results provided classification into three metabolic groups in which the betulin concentration was high, moderate, or low. The results show that HR-MAS NMR is rapid for fingerprinting of betulin and betulinic acid in the bark of B. utilis, while minimizing the drawbacks associated with solvent extraction. 相似文献
57.
A series of novel N′-([2-aryl-5-methyl-1,3-oxazole-4-yl]methylene)isonicotino/nicotino hydrazides 10a-l were prepared by the condensation reaction of 2-aryl-5-methyl-1,3-oxazole-4-carbaldehydes 8a-f with the corresponding isonicotino/nicotino hydrazides 9a/9b . The structures of the new compounds were elucidated by various spectroanalytical techniques, including IR, 1H NMR, 13C NMR, elemental (C,H,N), and mass analysis. All the newly prepared INH-1,3-oxazole hybrids were evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv. Among all the synthesized hybrids, compounds 10c and 10i derivatives displayed highest antitubercular activity with minimal inhibitory concentration 1.56 μg/mL. Further, molecular docking studies against the InhA enzyme were carried out to understand the interactions between potent hybrids and the target enzyme. Thus, these kind hybrids have the potentiality for the discovery of new antitubercular agents for deployment in the control and eradication of tuberculosis. 相似文献
58.
A new zwitterionic salt, sulfated choline based heteropolyanion, which was reported earlier by our group, has been found to be very effective for the synthesis of spirooxindole derivatives at room temperature. The heteropolyanion based on sulfated ionic liquid (HIL) showed promising features for the reaction, such as shorter reaction time, high product yields (about 90–95%), simple work up, easy removal, and reusability of the catalyst for several times without significant loss in its efficiency. This has made the protocol sustainable and economic. 相似文献
59.
60.
Shailesh N. Vajekar 《合成通讯》2020,50(8):1147-1158
AbstractA sustainable one-pot three-component synthesis of novel 1H-pyrazolo[1,2-a]pyridazine-2-carbonitrile derivatives employing a highly efficient, biodegradable, and recyclable choline hydroxide catalyst under solvent-free conditions is demonstrated. The salient features of this protocol are simple workup, mild reaction conditions, short reaction time (10?min), excellent yields (up to 97%), high atom economy, column chromatography-free protocol, and eco-friendliness. Interestingly, the choline hydroxide was recycled up to five cycles without any considerable loss of efficiency. The structures of the products were deduced by their 1H NMR, 13C NMR, and HRLC-MS spectra. 相似文献