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71.
Venkata Swamy Tangeti Kattaru Ramesh Babu G. V. Siva Prasad Tadikonda Ramu C. Venkata Rao 《Journal of the Iranian Chemical Society》2018,15(4):823-829
An efficient and rapid method was developed for the synthesis of C3-pyranopyrazole-substituted coumarins from one-pot five-component reaction of β-keto ester, hydrazine, O-hydroxy aromatic aldehydes, 6-methyl, 4-hydroxy pyranone and aromatic aldehyde in the presence of tri-ethylamine in solvent-free conditions. The microwave-assisted method reported herein offers advantageous shorter reaction times, higher yields and cleaner reaction compared with conventional heating methods. 相似文献
72.
The key steps in the enantioselective synthesis of Tamiflu include an asymmetric Diels-Alder reaction, Mitsunobu inversion using Fukuyama modified Weinreb reagent, carbamate directed epoxidation. Epoxide opening with trimethylsilyl azide furnished a 3:1 mixture of regioisomers that converged to afford the same aziridine. Attempted preparation of the unsaturated ester regioselectively using 2-iodoxybenzoic acid (IBX) following Nicolaou’s protocol failed. The unsaturated ester was prepared by phenylselenylation followed by selenoxide elimination. 相似文献
73.
D. Thangaraju S. Moorthy Babu P. Samuel A. Durairajan Y. Hayakawa 《Journal of Sol-Gel Science and Technology》2011,58(2):419-426
KGd(WO4)2 (KGW) particles were synthesized at 3.5, 5.5 and 7.5 pH values by Pechini polymeric complex sol–gel method using potassium nitrate, gadolinium nitrate, ammonium paratungstate, citric acid and ethylene glycol as starting materials. Deionized water was used as solvent. Polymeric precursor gel was formed with citric acid as complexing agent and ethylene glycol as binder. Synthesized gel was analyzed by FT-IR spectroscopy. Prepared precursor gels were further annealed using resistive and microwave processes at 550 and 700 °C, respectively. The properties of heat treated samples were characterized by powder XRD, FT-IR, Raman and SEM analysis to understand the crystallinity, organic liberation, tungstate ribbon formation and surface morphology, respectively. The phase formation and different phases of intermediate oxides in pre-fired samples were investigated by powder XRD. Organic liberation in the samples in relation to temperature, and the carbon content in the pre-fired powder was analyzed using FT-IR spectrum. Raman spectrum reveals the formation of tungsten ribbons as well as the quality of the samples. The morphological changes at different synthesis conditions were observed with SEM micrographs. 相似文献
74.
Considering impurity doping in small sized carbon nanotubes of diameter around 0.4 nm, we have calculated the donor binding energy by increasing the dopant concentration through a screening function that includes the curvature effect. We could observe the sudden fall in donor binding energy and metallic behaviour of the smaller single walled carbon nanotubes around 1011/cm2 (0.0026%) of impurity concentration. This result is useful for nano electronic device application such as nano diodes and switches. 相似文献
75.
Birendra Babu Adhikari Cuong-Alexander To Tetsuo Iwasawa 《Supramolecular chemistry》2013,25(10):724-730
Calix[6]arene hexacarboxylic acid binds instantly and with low symmetry to Pb, Sr and Ba. Later a highly symmetric up-down alternating conformation emerges. The solution structures are identical to their p-tert-butylcalix[6]arene hexacarboxylic acid counterparts. With either receptor, an octahedral cage is formed around the metal. The transformation from low to high symmetry however proceeds at significantly faster rates for the de-t-butylated host. 相似文献
76.
Mohammad Bodiuzzaman Atanu Ghosh Korath Shivan Sugi Abhijit Nag Esma Khatun Babu Varghese Ganesan Paramasivam Sudhadevi Antharjanam Ganapati Natarajan Thalappil Pradeep 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(1):195-200
Two ligand‐protected nanoscale silver moieties, [Ag46(SPhMe2)24(PPh3)8](NO3)2 and [Ag40(SPhMe2)24(PPh3)8](NO3)2 (abbreviated as Ag46 and Ag40, respectively) with almost the same shell but different cores were synthesized simultaneously. As their external structures are identical, the clusters were not distinguishable and become co‐crystallized. The occupancy of each cluster was 50 %. The outer shell of both is composed of Ag32S24P8, which is reminiscent of fullerenes, and it encapsulates a well‐studied core, Ag14 and a completely new core, Ag8, which correspond to a face‐centered cube and a simple cube, respectively, resulting in the Ag46 and Ag40 clusters. The presence of two entities (Ag40 and Ag46 clusters) in a single crystal and their molecular formulae were confirmed by detailed electrospray ionization mass spectrometry. The optical spectrum of the mixture showed unique features which were in good agreement with the results from time‐dependent density functional theory (TD‐DFT). 相似文献
77.
CH.B. Praveena Devi K. Vijay B. Hari Babu Syed Farooq Adil M. Mujahid Alam M. Vijjulatha Mohd. Bismillah Ansari 《Journal of Saudi Chemical Society》2019,23(7):980-991
A novel series of conjugates of benzosuberone and 1,2,3-triazole i.e. 3-(4-phenyl-1H-1,2,3-triazol-1-yl)propyl-9-chloro-2,3-dimethyl-6,7-dihydro-5H-benzo[7]annulene-8-carboxylic acids (8a-j) were synthesized in good to excellent yields catalysed by CuSO4 under milder reaction conditions and evaluated for their anti-proliferative activity. The structural elucidation of the prepared compounds was carried out using IR, 1H NMR, 13C NMR and Mass spectral analysis. The newly synthesized derivatives (8a-j) were evaluated for their anti-proliferative activity against four human cell lines and the novel derivatives showed moderate to excellent activity. The obtained results suggest that these compounds can be considered as new hits for anti-proliferative drug development programme and further SAR studies can help obtain better anticancer agents. 相似文献
78.
A non-enzymatic sensor was developed for the determination of glucose in alkaline medium by anodisation of copper in sodium potassium tartrate solution. The morphology of the modified copper electrode was studied by scanning electron microscopy, and its electrochemical behavior by cyclic voltammetry and electrochemical impedance spectroscopy. The electrode enables direct electrocatalytic oxidation of glucose on a CuO/Cu electrode at 0.7 V in 0.1 M sodium hydroxide. At this potential, the sensor is highly selective to glucose even in the presence of ascorbic acid, uric acid, or dopamine which are common interfering species. The sensor displays a sensitivity of 761.9 μA mM?1 cm?2, a linear detection range from 2 μM to 20 mM, a response time of <1 s, and a detection limit of 1 μM (S/N = 3). It was tested for determination of glucose level in blood serum. 相似文献
79.
C. Suresh Reddy Y. Hari Babu N. Ravi Sankar C. Devendranath Reddy 《Journal of heterocyclic chemistry》2004,41(6):1027-1031
Novel 3‐(substituted)‐2,4,8,15‐tetroxa‐3‐phosphadispiro[5.2.5]hexadecane‐3‐oxides (3‐12) have been synthesized by cyclization of 1,5‐dioxaspiro[5.5]undecande‐3,3‐dimethanol (1) with various substituted aryl phosphorus dichloridates (2) in dry toluene‐THF in the presence of triethylamine at 40‐60 oC. Their molecular structures were determined by ir, nmr and mass spectral studies and were screened for antifungal activity against Curvularia lunata and Aspergillus niger, and antibacterial activity on Staphylococcus aureus and Escherichia coli. Most of them possess significant activity. 相似文献
80.
The reactions of an N-acyliminium ion pool with alkenes and alkynes gave gamma-amino alcohols and beta-amino carbonyl compounds, respectively, after treatment with H(2)O/Et(3)N. The present reaction serves as an efficient method for cationic carbohydroxylation of alkenes and alkynes. When vinyltrimethylsilane was used as an alkene, the reaction was highly diastereoselective and served as an access to an enantiomerically pure alpha-silyl-gamma-amino alcohol. [reaction: see text] 相似文献