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81.
A Facile Diversity‐Oriented Multicomponent One‐Pot Synthesis of 3‐Amino‐6,7‐dihydrobenzo[c]thiophen‐4(5H)‐one Derivatives from α‐Oxo‐N,S‐ketene Acetal
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Swapnil G. Yerande Sunil D. More Mayur Bhandari Kiran M. Newase Kareem Khoury Kan Wang Alexander Dömling 《Journal of heterocyclic chemistry》2014,51(Z1):E358-E363
A convenient one‐pot multicomponent method for the preparation of 3‐amino‐6,7‐dihydrobenzo[c]thiophen‐4(5H)‐one derivative has been developed. Reaction of 1,3‐cyclohexanedione and phenyl isothiocynate gave α‐oxo‐N,S‐ketene acetal that were reacted in situ with 2‐chloromethylquniazoline‐4‐one derivatives, in the presence of sodium hydride to afford the target compound in reasonable overall yields. 相似文献
82.
Kiran Kumar Varma ChakrahariRajendra Singh Dhayal Sundargopal Ghosh 《Polyhedron》2011,30(6):1048-1054
Pyrolysis of an in-situ generated intermediate, produced in the reaction of [Cp∗MoCl4], 1, (Cp∗ = η5-C5Me5) with [LiBH4·THF], with an excess of difuryl ditelluride in toluene at 90 °C yielded syn and anti isomers of [Cp∗Mo(O)(μ-Te)]2 (2, 3) and [Cp∗2Mo2O2(μ-O)(μ-Te)] (4, 5). In a similar fashion, dibenzyl diselenide yielded syn and anti isomers of [Cp∗Mo(O)(μ-Se)]2 (6, 7), along with the known nido-[(Cp∗Mo)2B4H8Se2]. Note that in parallel with 2-7, [(Cp∗Mo)2B5H9] was isolated as the major product in both cases. Compounds 2-7 have been isolated in modest yield as orange to brown crystalline solids. All the new compounds have been characterized in solution by mass, IR, 1H, 13C, 77Se and 125Te NMR spectroscopy, and the structural types were unequivocally established by crystallographic analysis of 2-4 and 7. 相似文献
83.
84.
The essential oil of Eucalyptus cinerea is reported to possess a higher 1,8-cineole content than other Eucalyptus species. Variations in the quantitative and qualitative characteristics of E. cinerea oil produced by hydrodistillation (HD) and supercritical carbon dioxide extraction (SCE) techniques and a comparison between glycoside-bound and free volatile constituents produced by HD have been studied. It was found that HD produced higher oil (free volatiles) content (3.1%) as compared with SCE (1.1%), whereas bound volatiles constituted only about 0.4%. Gas chromatographic (GC) analysis of the oil samples revealed significant difference in their chemical composition. The essential oil (free volatiles) produced by HD contained 1,8-cineole (85.1%) as the major constituent, followed by a-terpineol (7.2%) and limonene (4.4%). In the bound volatile fraction produced by HD, 1,8 cineole (20.6%), alpha-terpineol (7.6%), p-cymene (6.3%), and limonene (4.5%) were found as major constituents. The extract produced by SCE was dominated by 1,8-cineole (70.4%), a-terpineol (8.6%), globulol (3.1%), aromadendrene (2%), citronellal (1.7%), viridiflorol (1.3%), phytol (1.1%) and terpinen-4-ol (1%). Although HD produced higher oil yields, SCE produced better extract in terms of the number of components detected. 相似文献
85.
Kiran S Kedlaya 《Comptes Rendus Mathematique》2002,335(11):921-926
We prove that every projective, geometrically reduced scheme of dimension n over an infinite field k of positive characteristic admits a finite morphism over some finite radicial extension k′ of k to projective n-space, étale away from the hyperplane H at infinity, which maps a chosen Weil divisor into H and a chosen smooth geometric point of X not on the divisor to some point not in H. To cite this article: K.S. Kedlaya, C. R. Acad. Sci. Paris, Ser. I 335 (2002) 921–926. 相似文献
86.
Dipak Prajapati Dhrubojyoti D. LaskarBaikuntha J. Gogoi Gitali Devi 《Tetrahedron letters》2003,44(35):6755-6757
The indium-catalysed coupling of propargyl bromide with a variety of imines and imine oxides afforded the corresponding propargylated products in high yields under mild conditions. 相似文献
87.
D. Udayakumar A. John Kiran A. Vasudeva Adhikari K. Chandrasekharan G. Umesh H.D. Shashikala 《Chemical physics》2006
The third-order nonlinear optical properties of newly synthesized soluble polyoxadiazoles containing 3,4-dialkoxythiophenes were investigated by using Z-scan and degenerate four-wave mixing (DFWM) techniques. The measurements were performed at 532 nm with 7 ns pulses from a Nd:YAG laser. We found a good agreement between the values of χ(3) determined from both the experiments. Z-scan results indicate a negative nonlinear refractive index, n2, whose magnitude is of the order of 10−10 esu for all the copolymers. The variation of nonlinear response among the copolymers clearly indicates the dependence of χ(3) on donor and acceptor type of units present in these copolymers. The copolymers exhibit strong reverse saturable absorption and good optical limiting properties at 532 nm. 相似文献
88.
T. Kiran Kumar S. Venkataratnam K. Venkata Reddy 《Radiation Physics and Chemistry》1996,48(6):707-710
Effective atomic numbers (Zeff) of different clay minerals are calculated for total photon interaction in the energy region 10 keV–10 MeV. The variation of Zeff with energy is discussed by comparing with the similar studies made for alloys and compounds from our laboratory. 相似文献
89.
90.
Rajiv Manohar Abhishek Kumar Misra Satya Prakash Yadav A.K. Prajapati 《Journal of Physics and Chemistry of Solids》2010,71(12):1684-1689
Dielectric measurements have been carried out for the determination of real and imaginary parts of the permittivity of a newly synthesized, unusually shaped liquid crystal. The sample has been investigated in the frequency range from 100 Hz to 10 MHz within a temperature range 80-130 °C. The dielectric measurements in the smectic A phase indicate a Cole-Cole type of dispersion, and the activation energy was found to be 5.5 meV by using the Arrhenius plot of relaxation time. In addition to this, thermal and optical transmittance studies have also been conducted in the above mentioned temperature range, and the temperature dependence of these parameters has been discussed in detail. The phase transition temperature obtained from a differential scanning calorimetry (DSC) study matches within 2 °C that was obtained from an optical transmittance study. The dielectric and optical behavior of the unusually shaped liquid crystal has been explained on the basis of a proposed theoretical model in which a sample possesses two different conformers having induced polarizations in opposite directions. 相似文献