共查询到20条相似文献,搜索用时 203 毫秒
1.
以对甲苯磺酰氯和邻氨基苯甲酸甲酯为原料,通过酰胺化、酰亚胺和卤代烃的缩合、克曼环化及水解脱羧等反应,合成盐酸考尼伐坦关键中间体N-甲苯磺酰基苯并氮杂卓-5-酮。在合成过程中,分别减少了有毒溶剂吡啶的用量,用叔丁醇钾代替怕水易爆的氢化钠,用容易购买回收的2-甲基四氢呋喃代替丁酮为溶剂,目标化合物的总收率由55%提高至63%,纯度达到99%以上。所得化合物经熔点、核磁共振氢谱等得到确认。该工艺显著地提高了中间体的产量及质量,因而提高了盐酸考尼伐坦的产率。 相似文献
2.
3.
以2-乙烯基苯甲酸甲酯及其衍生物为原料,经过酯水解反应,随后发生环氧化、环合反应制备了3-羟甲基异苯并呋喃-1(3H)-酮及其衍生物;再和三溴化磷或者对甲苯磺酰氯发生亲核取代,最后通过消除反应合成了3-亚甲基异苯并呋喃-1(3H)-酮及其衍生物.在亲核取代和消除反应中,对甲苯磺酰氯法比三溴化磷法产率高.目标产物及其中间体有10个是新化合物.化合物结构用1H NMR,13C NMR,MS和IR表征.目标产物在空气中长期放置没有发生二聚. 相似文献
4.
用IBX对醋酸去氢表雄酮选择性脱氢合成3β-乙酰氧基-雄甾-Δ5,15-二烯-17-酮 总被引:1,自引:0,他引:1
以醋酸去氢表雄酮为起始原料,于温度为65~70℃的DMSO-甲苯混合溶剂中,反应时间为22 h,利用二碘酰基苯甲酸(IBX)对醋酸去氢表雄酮的选择性脱氢简便高效地合成了曲螺酮关键中间体3β-乙酰氧基-雄甾-△4,15-二烯-17-酮;探讨了IBX与醋酸去氢表雄酮的摩尔比对目标化合物的收率影响.实验表明.在n(IBX):n(醋酸去氢表雄酮)=1.5∶1.0时,目标化合物的收率最佳,达到73%.目标化合物经紫外光谱、红外光谱、核磁共振氢谱、质谱及元素分析测试技术确证了其化学结构. 相似文献
5.
6.
以脱氢枞胺为原料,经氨基酰化、12位乙酰化、与对甲苯磺酰肼形成对甲苯磺酰腙衍生物,再通过卡宾中间体与C60进行[2+1]环加成反应合成了C60-脱氢枞胺衍生物。目标化合物经IR,UV-Vis,1H NMR,13C NMR,MALDI-TOF MS表征,所得化合物为[6,6]闭环结构C60加成产物。 相似文献
7.
8.
9.
10.
我们已报道了1-对甲苯磺酰基-2-苯氧基-3-芳基-4-苯基-1,4,2-二氮磷酰杂环戊-5-酮的合成及除草活性[1],为了进一步探讨3-位取代基的变化对这类1,4,2-二氮磷酰杂环戊-5-酮的除草活性的影响,按如下方法合成了相应的3-位烷基取代的1-对甲苯磺酰基-4-苯基-1,4-二氮-2-磷酰杂环戊-5-酮(2),并对脂肪醛与1及亚磷酸酯的酸催化反应机理进行了初步探讨.用元素分析、NMR、MS证实了化合物2的结构.初步除草活性测定结果表明,2具有一定的除草活性;其除草活性比相应的3-位芳基取代类化合物的低[1].R:2a,H;2b,Me;2c,Et;2d,n-Pr… 相似文献
11.
12.
A. A. Konarev E. A. Lukyanets V. M. Negrimovskii 《Russian Journal of Electrochemistry》2007,43(11):1252-1259
The electroreduction of methyl 5-nitro-4-oxopentanate was studied by means of a polarographic method and preparative electrolysis in acidic-alcoholic solutions. The effects of the following factors on the yield and quality of 5-amino-4-oxopentanoic acid hydrochloride were studied: the cathode material, amount of electricity, temperature, nature of the solvent, concentrations of the initial nitro compound and hydrochloric acid, and the cell design. It was shown by electrolysis at a controlled potential and in a galvanostatic mode that the products of methyl 5-nitro-4-oxopentanate electroreduction are hydroxyamino and amino compounds, and also ammonium chloride, nitromethane, methylhydroxylamine hydrochloride, and monomethylamine hydrochloride. Their ratio depends on the electrolysis conditions. The highest overall substance yield (61.1–66.0%) and current yield (68.1–68.6%) of 5-amino-4-oxopentanoic acid hydrochloride was achieved at a copper cathode in a filter-press cell. The content of the main substance in the electrochemically obtained samples of 5-amino-4-oxopentanoic acid was 89.5–91.0%. 相似文献
13.
《Tetrahedron》1988,44(23):7109-7118
A one pot synthesis of benzo [g] indolo [2,3-a] indolizinone-5 is described. Starting from tryptamine hydrochloride and methyl o-phthalaldehydic acid ester, 85% yield is obtained in refluxing n-butanol. In spite of differences with published data, the structure of final compound has been firmly established by 2D heteronuclear correlation NMR spectroscopy. 相似文献
14.
探索了用植物源商业原料合成熊去氧胆酸的新方法. 以醋酸去氢表雄酮为原料, 以区域选择性烯丙位氧化、 Mistunbu反应和Luche还原为关键步骤, 通过9步反应, 以38.6%的总收率合成了熊去氧胆酸. 其中, 关键中间体4由化合物3经改进的烯丙位氧化反应以较高产率获得. 对关键的烯丙基氧化反应的条件进行了优化, 包括溶剂、 氧化剂和反应温度. 该方法原料易得、 产率较高, 并且有效地避免了动物源性原料的风险, 易于实现规模化合成, 因而具有较高的应用价值. 相似文献
15.
An improved synthesis of ethyl N-[(2-Boc-amino)ethyl]glycinate and its hydrochloride salt is reported. The synthesis is based on the reductive alkylation of Boc-ethylenediamine with ethyl glyoxylate hydrate and furnishes the title compound in near quantitative yield and high purity without chromatography. This compound is suitable, as is, for the synthesis peptide nucleic acid monomers. Further, conversion to the hydrochloride salt provides a stable, nonhygroscopic solid that is a convenient form for handling and storage. 相似文献
16.
A new method for the synthesis of ramosetron hydrochloride, the most wildly used 5-HT3 receptor antagonist, was reported. The intermediate 8 was obtained in a high e.e. value via lipase catalyzed hydrolytic kinetic resolution. Then enantiomerically pure ramosetron hydrochloride was synthesized in two steps with excellent yield (the total yield is 24.6%). The method provides a new environment friendly and atom economy way to synthesize enantiomerically pure ramosetron. 相似文献
17.
5-硝基-6-羟基-2-(对甲氧羰基苯基)苯并噁唑的合成 总被引:1,自引:0,他引:1
研究了以关键中间体4-氨基-6-硝基间苯二酚盐酸盐(ANR·HCl)和对苯二甲酸单甲酯(MTA)为原料,分别经酰氯化、缩合、环合分步或原位合成AB型新单体前体--4-(5-硝基-6-羟基-2-苯并噁唑基)苯甲酸甲酯(MNB)的技术。 反应优化条件:在甲基异丁基酮溶剂中,n(ANR·HCl)∶n(MTA)=1.00∶1.03,115 ℃缩合反应2.5 h;m(ANR·HCl)∶m(PPA)=1.00∶3.25的多聚磷酸(PPA),120 ℃环合8.5 h;MNB收率75.68%(以ANR·HCl计),HPLC测定ω(MNB)=96.32%。 产物结构经1H NMR和IR确证。 相似文献
18.
19.
Shirish A. Patil Brian A. Otter Robert S. Klein 《Journal of heterocyclic chemistry》1993,30(2):509-515
The synthesis of several new thieno[3,4-d]pyrimidine C-nucleosides 5-8 is described. The known 5-ribosyl-ated methyl 4-(formylamino)thiophene-3-carboxylate key intermediate 20 was obtained as a mixture of anomers in significantly improved yield by condensation of the sugar 15 with methyl 4-(formylamino)thio-phene-3-carboxylate 19 in nitromethane at 60° in the presence of stannic chloride. Attempts to prepare the C-7 ribosylated compound 21 β by direct condensation of the bicyclic base 10 with 15 gave instead the N-1 ribosylated nucleoside 16 . The synthesis of the corresponding and previously unknown thieno[3,4-d]pyrimi-dine bases 12 and 13 is described along with stability studies on the 4-methylthio derivative 12 . Preliminary biological studies indicate that adenosine analogue 7 is a potent growth inhibitor of several mammalian tumor cell lines. 相似文献
20.
Panella L Aleixandre AM Kruidhof GJ Robertus J Feringa BL de Vries JG Minnaard AJ 《The Journal of organic chemistry》2006,71(5):2026-2036
Enantioselectivities up to >99% ee were achieved in the rhodium-catalyzed asymmetric hydrogenation of N-formyl dehydroamino esters using monodentate phosphoramidites as chiral ligands. The substrates were synthesized by condensation of methyl isocyanoacetate with a range of aldehydes and with cyclohexanone. A highly convenient multigram scale one step synthesis of methyl 2-(formamido)acrylate was developed. This compound was used in the synthesis of methyl 2-(formamido)cinnamate via a solvent free Heck reaction. Moreover, full conversion and >99% ee were obtained in 1 h in the hydrogenation of methyl 2-(formamido)acrylate with 0.2 mol % catalyst and 2 bar hydrogen pressure. The versatility of the formyl protection was established by its removal under mild conditions. 相似文献