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The synthesis of 4‐isothiocyanatomethyl‐pyridine 4 in 36% yield by Hasegawa and Kotani (Japanese patent 49088878, 1974) has spurred us to investigate this preparation in detail. In addition to this compound, 4‐isothiocyanatomethylene‐4H‐pyridine‐1‐carboxylic acid ethyl ester 3 can be isolated. The synthesis of both compounds 3 and 4 were optimized to 75% and 50% yield respectively. Reaction of compound 3 with methylamine gave thiourea derivatives 5, the same product obtained on reacting 4‐isothiocyanatomethyl‐pyridine 4 with methylamine. We succeed in adjusting the reaction conditions to obtain high yield either from compound 3 or isothiocyanate derivatives 4. 相似文献
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Aladdin Shamilov 《Physica A》2007,382(2):465-472
In the present study we have formulated a generalization of entropy optimization problems (GEOP), proposed sufficient conditions for the existence of solution. We have suggested also a new method based on a priori evaluations and Newton's methods for calculation of Langrange multipliers. Mentioned method allows calculating Langrange multipliers by starting from arbitrary initial point for Newton's approximations of constructed auxiliary equation. The solution of auxiliary equation is chosen as initial point for second constructed auxiliary equation. The recurring mentioned process for finite time leads to achieve an initial point for Newton's approximations of given equation and allows to find its unknown solution. 相似文献
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I. S. Nizamov R. R. Shamilov G. R. Sabirzyanova E. I. Nikitin A. R. Burilov M. A. Pudovik 《Russian Journal of General Chemistry》2012,82(5):859-863
The use of ultrasonic irradiation in the reactions of trialkyl borates with octahydroxytetraoctyl[l 4] metacyclophane allowed us obtaining tetraalkoxyboratocavitands with higher yields and under milder conditions. We first obtained 1,3,2-dioxaborolane and 1,3,2-dioxaborinane derivatives of tetraoctyl[l 4]metacyclophane using ultrasonic irradiation. Boratocavitands were converted into the corresponding amine complexes with isobutylamine. 相似文献
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Hoda H. Fahmy Aladdin M. Srour Mohamed A. Ismail Mai A. Khater Rabah A. Serrya May A. El-Manawaty 《Research on Chemical Intermediates》2016,42(9):6881-6892
A new series of tri-substituted pyrazole derivatives were designed as anti-cancer agents and synthesized, starting with the formylation of semicarbazone via the Vilsmeier–Haack reaction to give 3-(4-bromophenyl)-1H-pyrazole-4-carbaldehyde I which was the precursor of compounds 1–9. The new chemical entities were screened for their anti-cancer activity on various human cancer cell lines, namely: hepatocellular carcinoma HepG2, breast cancer MCF-7, lung carcinoma A549 and prostatic cancer PC3. Most of the synthesized compounds showed remarkable activity on the tested cell lines, while compound 2 had the highest potency against the HepG2 cell line with an IC50 of 9.13 µM compared with doxorubicin (IC50 = 34.24 µM), the reference standard used in this study, and compound 7 was the most active on the rest of the three cell lines; MCF-7, A549 and PC3 (IC50 = 16.52, 6.52 and 9.13 µM, respectively) relative to IC50 = 20.85, 5.93 and 38.02 µM of the standard. Thus, some of the synthesized tri-substituted pyrazole derivatives, specially 2 and 7, have the potential to be developed into potent anticancer agents. 相似文献
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R. R. Shamilov V. I. Nuzhdin V. F. Valeev Yu. G. Galyametdinov A. L. Stepanov 《Technical Physics》2016,61(11):1698-1703
Multilayer systems consisting of layers of hybrid quantum dots are fabricated. The quantum dots with the CdSe/CdS core/shell structure are chemically synthesized and deposited on the surface of quartz glass that contains ion-synthesized silver nanoparticles in the near-surface region. Silver nanoparticles exhibit optical absorption owing to the localized surface plasmon resonance. Variations in the photoluminescence intensity of the layer related to an increase in the distance from the quartz surface with metal nanoparticles are studied. An increase in the photoluminescence intensity is observed under excitation in the spectral region of the plasmon absorption of silver nanoparticles. An optimal distance between the layers is determined to maximize the enhancement of the photoluminescence of quantum dots in the presence of the near field of metal nanoparticles. 相似文献
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