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111.
Recent advances in the synthesis of C-5-substituted analogs of 3,4-dihydropyrimidin-2-ones: A review
3,4-Dihydropyrimidin-2-ones act as a versatile scaffold in organic synthesis, which serves as a significant template for the development of various therapeutic agents and shows a wide spectrum of activities. The attractive application of 3,4-dihydropyrimidin-2-ones in organic synthesis is undoubtedly owing to C-5 ester group, which is responsible for the change in its bioactivity. Introduction of various groups like electron-withdrawing and electron-donating groups at positions 1, 2, 3, 5, and 6 greatly increased biological activity. Significant efforts have been undertaken to exploit different synthetic routes to synthesize various derivatives of 3,4-dihydropyrimidin-2-ones. This review article gives a comprehensive account of the synthetic utility of C-5 substitution of 3,4-dihydropyrimidin-2-ones used in the design and synthesis of different types of compounds with greater emphasis on recent literature. 相似文献
112.
Abstract
A facile and environmentally benign procedure for the synthesis of octahydroquinazolinone and biscoumarin derivatives in ionic liquids is reported. Octahydroquinazolinones were synthesized in the presence of trimethylsilyl chloride (TMSCl) while the synthesis of biscoumarins required no additive. The ability to reuse the ionic liquid, the high yields, and ease of purification are the important features of this process. 相似文献113.
Mukund G. Kulkarni Sanjay W. Chavhan Mayur P. Desai Yunnus B. Shaikh Dnyaneshwar D. Gaikwad Attrimuni P. Dhondge Ajit S. Borhade Vijay B. Ningdale Deekshaputra R. Birhade Nagorao R. Dhatrak 《Tetrahedron letters》2010,51(34):4494-6381
Application of Wittig olefination-Claisen rearrangement protocol for the short synthesis of furo[2,3-b]indoles is described. 相似文献
114.
115.
A. K. Rastogi Seema Hardikar 《International Journal of Infrared and Millimeter Waves》2001,22(5):703-714
The behaviour of attenuation losses in Coplanar waveguides (CPW) is studied for quasi-planar transmission lines with constant characteristic impedance (Z0) and resistivity, having different geometry's. This behavior helps in making a suitable choice of the type of structure and its dimensional parameters depending upon the application. Minimization of loss for a chosen substrate thickness, conductivity and impedance is analyzed. Dispersion characteristics of CPW have been plotted for various metallization thicknesses. A sensitivity analysis for effective dielectric constant with respect to various dimensional parameters of CPW is presented. 相似文献
116.
Sanjay Rajpal 《Discrete Applied Mathematics》1995,60(1-3):343-347
We define a class of codes that corresponds to a class of matroids called paving matroids. This class of codes includes maximum-distance-separable (MDS) codes, and some other interesting codes such as the (12,6) ternary Golay code. Some basic properties of these codes are established using techniques from matroid theory. Our results raise a natural existence question to which we obtain partial answers using known results about the non-existence of Steiner systems of the type S(t–1,t,2t). 相似文献
117.
The cerium(III) and neodymium(III) complexes of 5‐aminoorotic acid were synthesized and characterized by means of spectral data (IR, Raman, 1H NMR and 13C NMR) and elemental analysis. Significant differences in the IR spectra of the complexes were observed as compared with the spectrum of the ligand. A comparative analysis of the Raman spectra of the complexes with that of the free 5‐aminoorotic acid allowed a straightforward assignment of the vibrations of the ligand groups involved in coordination. 1H NMR and 13C NMR spectra confirmed the formation of the complexes. The ligand and the complexes were tested for the cytotoxic activities on the chronic myeloid leukemia‐derived K‐562, overexpressing the BCR‐ABL fusion protein, and the non‐Hodgkin lymphoma‐derived DOHH‐2, characterized by a rexpression of the antiapoptotic protein bcl‐2 cell lines. The results obtained indicate that the tested compounds exerted a considerable cytotoxic activity upon the evaluated cell lines in a concentration‐dependent manner, which enabled the construction of dose–response curves and the calculation of the corresponding IC50 values. Cytotoxicity towards tumor cells was determined for a broad concentration range. The inorganic salts exerted a very weak cytotoxic effect on these cells that is in contrast to the lanthanide complexes, which exhibited potent cytotoxic activity towards K‐562 and DOHH‐2 cell lines. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
118.
A. K. Rastogi S. Mishra M. Nigam A. K. Tiwari 《International Journal of Infrared and Millimeter Waves》1994,15(10):1709-1720
Dispersion characteristics and wave impedance of trapped coupled image guides are computed by using mode matching techniques. Dispersion curves for trapped coupled image guide are plotted for various dielectric materials and dimensional parameters. The hybrid directional couplers in the above configuration have been theoretically designed by computing the normalization propagation constant. 相似文献
119.
Saurabh Rastogi George E. Klingzing 《Particle & Particle Systems Characterization》1994,11(6):453-456
Avalanching of solids is an important multivariable dependent phenomenon that can be a valuable tool for characterization of solids flowability. Although avalanching by itself is primarily chaotic it appears that the fractal analysis of its avalanching mass data can yield very interesting and significant information that is of importance in determining suitability of a material in solids handling and pneumatic transport. 相似文献
120.
We study the problem ofsurfacedirected spinodal decomposition, viz., the dynamical interplay of wetting and phase separation at surfaces. In particular, we focus on the kinetics of wetting-layer
growth in a semi-infinite geometry for arbitrary surface potentials and mixture compositions. We also present representative
results for phase separation in confined geometries, e.g., cylindrical pores, thin films, etc. 相似文献