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设计合成了10个4-二甲氨基黄酮衍生物,产物结构均经1H NMR,ESI-MS和元素分析确认.采用噻唑蓝(MTT)法测试了化合物对HepG2(人肝癌细胞)的抑制作用,结果表明目标化合物在30μmol/L浓度下对HepG2细胞损伤均有一定的抑制作用,大部分化合物优于对照药物槲皮素,其中化合物5c,5e,5f和5j活性最强,抑制率分别为91.0%,90.1%,95.7%和92.1%,而且化合物5f在10μmol/L浓度下对HepG2的抑制率为93.1%,具有深入研究的价值. 相似文献
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4,4′-四甲二氨基二苯甲烷的合成 总被引:1,自引:0,他引:1
4,4′-四甲二氨基二苯甲烷为染料的重要中间体与铅试剂,并且还是环氧树脂固化的优良促进剂。文献中虽不乏其合成方法的报导,诸如,以盐酸为催化剂的经典的Cohen法,过氧化二乙酰法,以及过苯甲酸叔丁酯法等,唯其或收率低,或反应时间长,或原料成本高,或操作复杂,均欠理想。本文为Cohen法的改进,采用草酸-盐酸为混合催化剂,使甲醛与N,N一二甲苯胺经缩合反应合成之,并经正交实验提出合成的最佳反应条件。结果表明在与Cohen法相同的反应时间内可得到高得多的收率,而且产品纯度高,操作简便,反应时间短。 相似文献
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[reaction: see text] We report a novel and efficient diastereoselective synthesis of wiedemannic acid analogue 30 in 16 steps from 7 using a tandem oxy-Cope/Claisen/ene reaction as the key step. Comparison of NMR data between wiedemannic acid (1) and analogue 30 leads us to believe that the reported stereochemistry at the ring junction of 1 is incorrect. 相似文献
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The preparation of the fused bicycle 14 is reported together with its photocyclisation to the dioxinone 2. Base induced fragmentation of the photoadduct 15 formed exclusively in the aforementioned photocylisation, followed by Wittig methylenation gave the kainoid derivative 18. 相似文献
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《Tetrahedron: Asymmetry》2006,17(6):961-966
The enantioselective enzymatic desymmetrization (EED) of various 3-arylglutaric anhydrides 1 with alcohols in organic media has been studied. The effect of the solvent on the stereochemical outcome of the reaction was investigated in detail. The amount of biocatalyst was optimized, and the possibility of its re-use was tested. The first example of the EED of 3-substituted glutaric anhydrides with esters as nucleophiles is reported. 相似文献
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An asymmetric synthesis for the preparation of both enantiomers of trans-methylpipecolic acids is described. It is based on Sharpless epoxidation as a chirality source, regioselective ring opening with allylamine, and ring-closing metathesis to construct the piperidine ring. The stereogenic center at C-4 is set by stereoselective hydrogenation that is directed by the alcohol functionality of an intermediate and proceeds with good diastereomeric control (trans/cis 16/1). Crystallization of the Boc-protected amino acid afforded the target products with excellent chemical (98% de) and enantiomeric purity (99% ee). 相似文献
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The titled carboxylic acid ( 1 ) was prepared by condensation of 2-furylglyoxal with aminoacetamide followed by chlorination of the resulting 2-hydroxy-5-(2′-furyl)pyrazine ( 2 ) and permanganate oxidation. The acid was further converted into methyl ester and 5-hydroxypyrazinecarboxylic acid. 相似文献
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