共查询到20条相似文献,搜索用时 62 毫秒
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以2-氯-5-氯甲基吡啶(CCMP)、无水乙二胺和硝基胍为原料,运用串联反应方法合成了吡虫啉[化学名:1-(6-氯-3-吡啶甲基)-N-硝基-2-咪唑啉亚胺]。该方法反应中间体无需纯化处理,操作简单,同时解决了活性中间体进一步进行副反应的难题。通过单因素实验,探讨了pH、反应溶剂、温度以及时间等因素对产物收率的影响,得到的优化工艺条件为:以乙腈为溶剂,nCCMP∶n无水乙二胺∶n硝基胍=1∶5∶1,于30℃反应120min,产率可达96.35%。其结构经1H NMR、13C NMR、IR表征。 相似文献
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以2-氨基-4-甲氧基苯甲酸甲酯为原料,通过氯代反应,再分别通过酯水解反应得到化合物2-氨基-5-氯-4-甲氧基苯甲酸和2-氨基-3-氯-4-甲氧基苯甲酸。其中间体及产物结构经~1H NMR、~(13)C NMR和ESI-MS确证,并考察了最佳氯代反应条件。结果表明:物料配比为n(2-氨基-4-甲氧基苯甲酸甲酯)∶n(NCS)=1∶1. 2,反应溶剂为N,N-二甲基甲酰胺,反应时间为16 h,两种氯代产物2-氨基-5-氯-4-甲氧基苯甲酸甲酯和2-氨基-3-氯-4-甲氧基苯甲酸甲酯收率分别为47%和39%。 相似文献
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以2-氯-3-硝基-5-溴吡啶为起始原料,经取代反应、水解反应、Suzuki偶联反应得到6-甲基-5-硝基-3-吡啶硼酸频哪酯。反应总收率为51%,中间体及目标产物结构由IR和1H-NMR表征。 相似文献
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本文报道1-(5-二茂铁基-1,3,4-噻二唑-2-基)哌啶-2-酮(1)的合成。首先,在乙酸催化下,二茂铁甲醛(2)和氨基硫脲(3)反应得到二茂铁亚胺基硫脲衍生物(4)。然后,在三氯化铁作用下,中间体4发生关环反应得到5-二茂铁基-1,3,4-噻二唑-2-胺(5)。中间体5再与5-溴戊酰氯(6)发生N-酰基化反应得到5-溴-N-(5-二茂铁基-1,3,4-噻二唑-2-基)戊酰胺(7)。最后,在碱性条件下,中间体7发生分子内关环反应得到目标化合物(1)。中间体及产物结构经1H NMR、13C NMR和ESI-MS表征,产物1结构进一步通过X-单晶衍射确证。然后分别考察了中间体5及产物1收率的主要影响因素,确定中间体5合成的适宜条件为:三氯化铁的用量为n(三氯化铁)∶n(中间体4)=4∶1,反应温度80℃,反应时间为15 h,在该条件下,中间体5的收率达到61.9%;确定产物1合成的适宜条件为:反应溶剂为二氧六环,物料比为n(DIEA)∶n(6)∶(5)=3.0∶1.2∶1.0、反应温度为80℃,反应时间为4 h,在该条件下,产物1收率达到68... 相似文献
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以N-甲基-4-硝基苯胺作为起始原料,依次经氯乙酰化、取代及氢化还原反应制得关键中间体N-(4-氨基苯基)-甲基-2-(4-甲基-1-哌嗪基)乙酰胺(4);以4-氯-3-硝基苯甲酸为原料,依次经酯化、取代、氢化还原及环合反应制得6-甲氧羰基-2-吲哚酮(8); 8与原苯甲酸三乙酯和乙酸酐经“一锅煮”反应制得中间体1-乙酰基-3-甲氧基(苯基)亚甲烯基-2-氧代吲哚环-6-羧酸甲酯(9); 4和9进行取代反应的同时脱除保护,经“一锅煮”反应合成尼达尼布,总收率57.2%,其结构经1H NMR,13C NMR和MS(ESI)确证。 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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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 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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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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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
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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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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献