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991.
Naidong Ye Dan A. Smith J. Gregory Reid David R. Watson Pankaj Daga Stephen E. Gottschling 《合成通讯》2017,47(5):481-485
Incorporation of isotopes has long been used as a research tool to label carbons and elucidate biochemical pathways. More recently, H→D exchange has led to analogs of therapeutic agents with improved metabolic stability and properties. Such compounds also have the potential for an improved drug/drug interaction profile and may even avoid the formation of toxic metabolites. Hence, a clear need for an efficient access to deuterated intermediates on large scale has emerged. In the context of an ongoing drug discovery program, we required large quantities of morpholine-d8. We herein report the successful optimization of a one-pot process allowing a near complete exchange of all methylene hydrogens in morpholine to deuterium atoms using D2O as the sole source of deuterium and Raney Nickel as catalyst. This facile and safe protocol will be used to scale up the synthesis of morpholine-d8 in due course. 相似文献
992.
Plasma Treatment Enhanced Magnetic Properties in Manganese Doped Titanium Nitride Thin Films 下载免费PDF全文
The ferromagnetic manganese doped TiN films were grown by plasma assisted molecular beam epitaxy on MgO(001) substrates. The nitrogen concentration and the ratio of manganese at Ti lattice sites increase after the plasma annealing post treatment. TiN(002) peak shifts toward low angle direction and TiN(111) peak disappears after the post treatment. The lattice expansion and peak shift are mainly ascribed to the reduction of nitrogen vacancies in films. The magnetism was suppressed in as-prepared sample due to the pinning effect of the nitrogen vacancies at defect sites or interface. The magnetism can be activated by the plasma implantation along with nitrogen vacancies reduce. The decrease of nitrogen vacancies leads to the enhancement of ferromagnetism. 相似文献
993.
994.
Liang-Deng Nie Fei-Feng Wang Wei Ding Xiao-Xin Shi Xia Lu 《Tetrahedron: Asymmetry》2013,24(11):638-642
A novel azide-free asymmetric synthesis of oseltamivir phosphate 1 (Tamiflu®) starting from Roche’s epoxide is described. Roche epoxide 2 was converted into N-acetyl aminoalcohol 3 in 95% yield via a BF3·OEt2-catalyzed epoxide-opening with acetonitrile as a nucleophile. Compound 3 was then transformed into a methanesulfonate 4 in 98% yield. Compound 4 was converted into aziridine 5 in 91% yield. Aziridine 5 was subsequently converted into oseltamivir phosphate 1 via two paths (a and b). In the path a, compound 5 underwent aziridine-opening with diallylamine as a nucleophile to afford compound 7 in 93% yield; compound 7 could then be converted into oseltamivir phosphate 1 in 88% yield. In path b, compound 5 underwent aziridine-opening with isopropyl 2,2,2-trichloroacetimidate as a nucleophile to afford compound 8 in 94% yield, which was then converted into oseltamivir phosphate 1 in 82% yield. 相似文献
995.
996.
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998.
Xinying Zhang Xiaoyan Li Xuesen Fan Xia Wang Dongfang Li Guirong Qu Jianji Wang 《Molecular diversity》2009,13(1):57-61
One-pot multi-component reactions of aldehydes, cyanothioacetamide and malononitrile promoted by ionic liquid proved to be
an efficient way for the synthesis of thiopyran derivatives. Without any added catalyst, both aromatic and aliphatic aldehydes
participated in this reaction smoothly. As an application of this method, a pyrimidine nucleoside-thiopyran chimera with potential
biological activities was obtained in high yield from 5-formyl-2’-deoxyuridine. In addition, the ionic liquid used can be
easily recovered and effectively reused for at least 5 times.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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