排序方式: 共有18条查询结果,搜索用时 15 毫秒
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Chandrachood Pranav S. Jadhav Amol R. Garud Dinesh R. Deshpande Nirmala R. Puranik Vedavati G. Kashalkar Rajashree V. 《Research on Chemical Intermediates》2020,46(12):5219-5230
Research on Chemical Intermediates - A series of quinoxaline derivatives were efficiently synthesized by convenient and simple procedure in excellent yields using 1 wt.% of titanium silicate (TS-1)... 相似文献
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Vij Mohit Garse Harshal Dand Neha Kadam Vilasrao Hirlekar Rajashree 《Journal of inclusion phenomena and macrocyclic chemistry》2010,67(1-2):39-47
The inclusion behaviour of β-cyclodextrin (βCD) was studied toward Cefdinir (CEF) in order to enhance the solubility and dissolution rate, following cyclodextrin complexation. Drug cyclodextrin solid systems were prepared by conventional methods of kneading (KN), co-evaporation (CE), spray drying (SD) and with a novel approach of microwave irradiation (MWI). The formation of inclusion complexes with βCD in the solid state, were confirmed by Differential scanning calorimetry (DSC), Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) studies, and comparative studies on the in vitro dissolution of CEF were carried out. Characterization of binary system by DSC, FTIR and SEM indicated that SD and MWI method resulted in formation of true complexes. Binary systems showed significant increase in dissolution rate as compared to plain drug. Amongst the binary systems MWI products were prepared in least time with better yield and highest dissolution rate. 相似文献
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Mahale RY Arulkashmir A Dutta K Krishnamoorthy K 《Physical chemistry chemical physics : PCCP》2012,14(13):4577-4583
The impact of electron transfer (ET) from a series of band edge modulated polymers to atmospheric oxygen is examined in connection with substrate oxidation prevention. Polymers with the highest occupied molecular orbital (HOMO) energy level below and above the oxygen energy level were tested and the former showed better efficiency. Furthermore, the oxidation prevention efficiency of a polymer with lower HOMO increased by two orders of magnitude, when the pores on the film were filled with spherical molecules, [6,6]-phenyl-C61-butyric acid methyl ester. We found that the polymer surface hydrophobicity has little or no influence on oxidation prevention. It is interesting to note that a polymer with a hole mobility of 8 × 10(-10) cm(2) V(-1) s(-1) showed a two-fold increase in oxidation prevention efficiency compared to a polymer with a hole mobility of 6 × 10(-5) cm(2) V(-1) s(-1). Over all, from the concerted approach, we conclude that a polymer devoid of pores with the HOMO energy level below oxygen and low charge carrier mobility is a suitable candidate for prevention of substrate oxidation/corrosion. 相似文献
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Pranav Chandrachood Tushar Gadkari Nirmala Deshpande Rajashree Kashalkar 《Journal of the Iranian Chemical Society》2012,9(1):47-51
The oxidation of 1,4-dihydropyridines has been carried out using catalytic quantity of transition metal nitrates supported on silica gel under IR irradiation. The C-4 de-alkylation is found to be minimal due to milder reaction conditions. The new protocol has been found to be economic and environment friendly. 相似文献
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Rajashree Hirlekar Vilasrao Kadam 《Journal of inclusion phenomena and macrocyclic chemistry》2009,63(3-4):219-224
Aim of the present work was to investigate the effect of methyl-β-cyclodextrin (MβCD) on the solubility and dissolution rate of carvedilol (CAR), a drug used orally for the treatment of hypertension. Phase solubility studies showed an AL-type diagram indicating the formation of inclusion complex in 1:1 molar ratio. Solid binary systems of the drug with MβCD were prepared by various methods. Physicochemical characterizations were performed using Fourier Transformation Infrared Spectroscopy, Differential Scanning Calorimetry and powder X-Ray Diffractometry. It could be concluded that CAR can form inclusion complex with MβCD. The dissolution profiles of inclusion complexes were determined and compared with those of CAR alone and the physical mixture. The dissolution rate of CAR was increased by MβCD inclusion complexation remarkably. 相似文献
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Nalawade Pravin Aware Babasaheb Dand Neha Kadam Vilasrao Hirlekar Rajashree 《Journal of inclusion phenomena and macrocyclic chemistry》2009,65(3-4):377-383
In this work, we illustrate the usefulness of cyclodextrins, namely, methyl-β-cyclodextrin (MβCD), an amorphous, methylated derivative of the natural β-cyclodextrin, as a tool to form an inclusion complex with Valsartan (VAL), a poorly water soluble drug. The phase solubility study showed AL type of curve with slope less than one indicating the formation of complexes in 1:1 molar ratio of drug and CD. The stability constant was found to be 538.14 ± 5.4 Mole?1. Solid binary systems between VAL and MβCD were prepared experimentally in a stoichiometry 1:1 by different techniques (physical mixing, kneading, co-evaporation). Afterward these products were characterized by Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Scanning electron microscopy (SEM) and 1H Nuclear magnetic resonance study (1H NMR). The results obtained suggested that co-evaporation methods yield a higher degree of amorphous entities suggesting the formation of inclusion complex between VAL and MβCD. The dissolution of VAL from the binary systems was studied to select the most appropriate system for the formulation development. It was concluded that the preparation technique played an important role in the dissolution behavior of the drug and the inclusion complex between VAL and MβCD obtained by co-evaporation method allowed better performance. 相似文献
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Rahul Kalita Wahida Begum Poorvi Gupta Manav Chauhan Naved Akhtar Rajashree Newar Prof. Dr. Kuntal Manna 《欧洲无机化学杂志》2023,26(25):e202300215
Oxidation of alkenes to carbonyls or diols compounds is important in synthesizing fine chemicals and pharmaceutical intermediates. We report the synthesis and characterization of an aluminum metal-organic framework node-supported copper(II) chloride (DUT-5-CuCl), which is an efficient heterogeneous catalyst for the oxidation of alkenes using H2O2 as an oxidizing agent. Styrene and various substituted styrenes were transformed into the corresponding carbonyl compounds in excellent selectivity and yields. DUT-5-CuCl is tolerant with various functional groups and could be recycled and reused at least 5 times in the oxidation of α-methylstyrene. Unlike the oxidation of styrene derivatives, DUT-5-Cu catalyzed oxidation of aliphatic and cyclic alkenes produced 1,2-diols compounds selectively. The mechanism of the DUT-5-Cu catalyzed oxidation of styrene to benzaldehyde was investigated in detail by various experiments such as the determination of reaction intermediates and characterization of the catalyst after catalysis, and computational studies. This work highlights the importance of MOF-supported earth-abundant metal catalysts for oxidation reactions to produce fine chemicals. 相似文献