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1.
《有机化学》2015,(10)
以鸟苷(1)为原料,与乙酸酐经过糖环羟基保护反应,得到2',3',5'-三-O-乙酰基鸟苷(2);2与对甲苯磺酰氯反应,得到9-(2',3',5'-三-O-乙酰基-β-D-呋喃核糖)-2-氨基-6-对甲苯磺酰氧基嘌呤(3);3与亚硝酸异戊酯和二乙基二硫醚反应,得到9-(2',3',5'-三-O-乙酰基-β-D-呋喃核糖)-6-对甲苯磺酰氧基-2-乙硫基嘌呤(4);4经过胺解和脱糖环羟基保护反应得到10个未见报道的6-烷氨基-2-乙硫基嘌呤核苷化合物(5).化合物结构经1H NMR、13C NMR、IR和HRMS进行了表征,并对它们进行了抗血小板聚集活性测试,结果表明对抗血小板聚集显示一定的活性. 相似文献
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2,6-二甲基-3,5-二氯-4-吡啶酚糖苷的合成 总被引:4,自引:0,他引:4
在相转移催化条件下, 使 a-D-乙酰基化溴代的葡萄糖、半乳糖、葡萄糖醛酸甲酯1a, 1b, 1c分别与2,6-二甲基-3,5-二氯-4-吡啶酚(俗称氯吡醇, 氯羟吡啶)作用, 合成了氯吡醇的糖苷: 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基-β-D-葡萄吡喃糖苷(2a), 1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4,6-四-O-乙酰基β-D-半乳吡喃糖苷(2b), 1-O-(2'6'-二甲基-3',5'-二氯-4'-吡啶基)-2,3,4-三-O-乙酰基-β-D-葡萄吡喃糖醛酸甲酯(2c)。2a, 2b, 2c分别在甲醇中氨解, 相应得到: 1-O-(2', 6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖苷(3a), 1-O(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-半乳吡喃糖苷(3b),1-O-(2', 6'-二甲基-3',5'-二氯-(4'-吡啶基)-β-D-葡萄吡喃糖醛酸酰胺(3c)。2c用CH~3ONa/CH~3OH处理, 得到1-O-(2',6'-二甲基-3',5'-二氯-4'-吡啶基)-β-D-葡萄吡喃糖醛酸甲酯(3d)。 相似文献
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2,2-二甲基-8-乙酰基-7-羟基-5-甲氧基色满分别与对甲基苯甲酰氯,间氯苯甲酰氯和间三氟甲基苯甲酰氯经Baker-Venkataraman重排和关环反应合成了3个新型的苯并吡喃黄酮(3a~3c);1-(2″,4″-二甲氧基苯基)-3-(2',2'-二甲基-7'-羟基-5'-甲氧基色满-8')-1,3-二酮(4)分别与烯丙基溴,异戊烯基溴和碘甲烷经取代和关环反应合成了3个新型的3-烃基苯并吡喃黄酮(6a~6c)。3和6的结构经1H NMR,13C NMR和MS表征。采用MTT法和SRB法研究了3和6体外对人白血病细胞(K562)和人肺癌细胞(K549)的抗肿瘤活性。结果表明:2',4'-二甲氧基-2″,2″-二甲基-3″,4″-2H二氢吡喃-3-甲基-5″,6″:5,6-黄酮(6c)显示了较好的抗肿瘤活性。 相似文献
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2, 5-二取代基-1, 3, 4-恶二唑及恶二唑啉类化合物的合成 总被引:40,自引:0,他引:40
2-苯基-1,2,3-连三唑-4-甲酰肼(1)与芳酸在POCl~3催化下得到6种新的2-芳基-5-(2'-苯基-1',2',3'-连三唑-4'-基)-1,3,4-恶二唑(2)。1与羰基化合物缩合得到相应的酰腙(3),在Ac~2O作用下环化成2-取代基-3-乙酰基-5-(2'-苯基-1',2',3'-连三唑-4'-基)-1,3,4-恶二唑啉(4)。化合物的结构经元素分析,IR,^1HNMR和MS确证。 相似文献
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本文报道从5'-O-磺酰基-2',3'-O-异亚丙基尿核苷通过一步法合成N-烷基2',3'-O-异亚丙基异胞苷和从5'-O-对甲苯磺酰基尿核苷合成5'-脱氧-5'-异丙氨基尿核苷。并对以上产物形成的机制作了探讨。 相似文献
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以D-核糖为起始原料经缩酮化、酯化、NaBH_4在DMSO与石油醚(1∶0.5∶1.5)还原、水解、无水醋酸钠催化酰化制备中间体(6a6b)与5-氟胞嘧啶进行Silyl反应制备同一构型的5′-脱氧-2′,3′-二-O-乙酰基-5-氟胞苷(7),(7)再与氯甲酸正戊酯进行酰胺化,最后水解去除乙酰基得到卡培他滨,总收率42.17%。HPLC纯度为99.81%。该新合成方法原料廉价易购、反应条件温和、操作简单,适合工业化生产。 相似文献
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本文以价廉易得的D-核糖为起始原料,经缩酮化保护、磺酰化,1,4-二氧六环做溶剂的条件下,使用硼氢化钾还原、再经水解、乙酰化反应得到关键中间体1,2,3-三-O-乙酰基-5-脱氧-D-呋喃核糖,再与5-氟胞嘧啶进行Silyl反应制备5′-脱氧-2′,3′-二-O-乙酰基-5-氟胞苷,与氯甲酸正戊酯进行酰胺化,水解得到目标化合物卡培他滨(1),结构经1HNMR、13CNMR以及MS表征,总产率49.69%(以D-核糖计),HPLC测得纯度100.00%。该合成方法原料廉价易购、反应条件温和,改进后的路线操作简单,绿色环保,适合工业化生产。 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献
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Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献