共查询到20条相似文献,搜索用时 203 毫秒
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采用甲硫酯与NH2OH·HCl在室温条件下反应,合成了3-(2-对甲苯基乙烯基)-5(4H)-异唑酮,通过单晶X射线衍射确定了产物的结构.由1HNMR确定的构型与晶体结构完全一致,表明标题化合物在弱极性溶剂(如乙醚和氯仿)中是稳定的.半经验AM1和PM3计算的C7和C8净电荷(分别为-0.077,-0.101)可能是H7和H8化学位移(分别为6.83和6.96)很接近的主要原因.B3LYP/6-311G**基组计算的异构体能量数据表明,3-(2-对甲苯基乙烯基)-5(4H)-异唑酮是最稳定的构型 相似文献
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在KOH作用下,芳甲酰肼1a~1e与CS2环化生成5-芳基-2-巯基-1,3,4-噁二唑(2a~2e);将2a~2e与氯乙酸乙酯反应,生成2-(5-芳基-1,3,4-噁二唑)硫基乙酸乙酯(3a~3e);3a~3e肼解得2-(5-苯基-1,3,4-噁二唑-2-硫基)乙酰肼(4a~4e);4a~4e与芳酰基异硫氰酸酯5a~5d反应得到双酰基氨基硫脲衍生物A1~A19;A1~A19在H2SO4催化下环合得到目标化合物B1~B19;目标化合物的结构经IR,1H NMR,MS,HRMS确证. 相似文献
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新型含异噁唑环的喹唑啉衍生物的合成和抑蛋白酪氨酸酶 α和ε活性研究 总被引:1,自引:0,他引:1
以2-氨基-4-硝基-苯甲酸和醋酸甲脒为原料, 合成了7-硝基-喹唑啉酮(3), 化合物3在SOCl2的作用下氯代得7-硝基-4-氯-喹唑啉(4); 又以取代苯甲醛为起始原料, 通过合成肟、1,3偶极环加成反应、甲磺酰化、叠氮化、Zn/NH4Cl 还原得中间体3-(取代苯基)-异噁唑-5-甲胺衍生物5a~5e. 4与5a~5e在碱性氧化铝作用下固相研磨合成了5种未见文献报道的新型的含异噁唑环的喹唑啉衍生物6a~6e. 所合成的化合物通过IR , 1H NMR, MS等分析方法进行了表征. 体外抑蛋白酪氨酸酶α (PTPα)和蛋白酪氨酸酶ε (PTPε)活性测试结果表明测试样品浓度在20 μg/mL下对PTPα和PTPε均无显著的抑制活性. 相似文献
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Theopeningoftheringof5(4H)-oxazolonesisoneofthemethodsforthesynthesisof-..-non-racemica-aminoacids.Thediastereoselectivering-openingof5(4H)-oxazolonesbychiralnucleophilesandenantioselectivehydrolysisandalcoholysisof5(4H)-oxazolonesbyenzymeshavebeenextensivelyinvestigated'.However,toourknow1edgenon-enzymecatalyzedenantioselectivealcoholysisof5(4H)-oxazoloneshasnotbeenreported.Inthispaper,wereportonthefirstnon-enzymecatalyzedenantioselectivealcoholysisof5(4H)-oxazolonesbycinchonine.As4-substit… 相似文献
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Roman Mazurkiewicz Agnieszka Pa?dzierniok-Holewa Miros?awa Grymel 《Tetrahedron letters》2008,49(11):1801-1803
4-Phosphoranylidene-5(4H)-oxazolones 1 undergo hydrolysis in THF in the presence of HBF4 at room temperature to give N-acyl-α-triphenylphosphonioglycines 3 (R2 = H) in very good yields. 4-Alkyl-4-triphenylphosphonio-5(4H)-oxazolones 2 react with water in CH2Cl2/THF solution without any acidic catalyst at 0-5 °C in a few days yielding N-acyl-α-triphenylphosphonio-α-amino acids 3 (R2 = Me) or α-(N-acylamino)alkyltriphenylphosphonium salt 4 (R2 = CH2OMe). α-Triphenylphosphonio-α-amino acids 3, on heating up to 105-115 °C under reduced pressure (5 mmHg) or on treatment with diisopropylethylamine in CH2Cl2 at 20 °C undergo decarboxylation to give the corresponding α-(N-acylamino)alkyltriphenylphosphonium salts 4, usually in very good yields. 相似文献
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使用B(C6F5)3替代稀有金属催化剂,实现了绿色、无毒、温和催化吲哚与苯乙炔的加成反应.对吲哚不同位置带有取代基的底物进行拓展,在室温条件下高产率获得了一系列双吲哚烷烃.对机理的初步探究表明,反应首先从苯乙炔被B(C6F5)3活化开始,而后依次受到两分子吲哚进攻,经马氏加成得到相应产物.根据探究结果,给出了可能的反应机理. 相似文献
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Nasim Seifi M. Hassan Zahedi-Niaki M. Reza Barzegari Abolghasem Davoodnia Raheleh Zhiani Amir Aghaei Kaju 《Journal of molecular catalysis. A, Chemical》2006,260(1-2):77-81
Reaction of 6-hydrazino-1,5-diphenyl-1H-pyrazolo[3,4-d]pyrimidine-4-imine with aromatic aldehyde in presence of Preyssler catalyst yielded 8-aryl-1H-pyrazolo[4,3-e][1,2,4]triazolo[4,3-a] pyrimidine-4(5H)-imine. The performance of different form of Preyssler's anions including H14[NaP5W30O110], H14-P5, mixed-addenda H14[NaP5W29 MoO110], H14-P5Mo, silica supported H14[NaP5W30O110]/SiO2 and H14-P5/SiO2 have been investigated. The reaction results were compared with that of a conventional acid catalyst (H2SO4). 相似文献
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报道应用aza-Wittig反应,采用易得的原料,在温和的条件下,以78%~90%的产率有效的合成了新型2-氨基-呋喃并[3,2-d]嘧啶-4(3H)-酮衍生物5,其结构经IR,1H NMR,MS和元素分析确认.为进一步得到结构确认,化合物5c经X射线衍射分析证实.运用噻唑蓝(MTT)标准法对化合物5进行了体外抗肿瘤活性的测定,其中5f对肺癌细胞A459的IC50值为18.4μmol/L,显示出潜在良好的抗肿瘤活性. 相似文献
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以糠醛为原料,经氧化、醚化和重结晶制得5-甲氧基-3,4-二溴-2(5H)-呋喃酮(4); 4与哌嗪经Michael加成消除反应制得5-甲氧基-4-哌嗪基-3-溴-2(5H)-呋喃酮(5); 5与取代磺酰氯经磺酰化反应合成了7 个新型的含哌嗪-磺酰胺的2(5H)-呋喃酮类化合物(7a~7g),其结构经1H NMR, 13C NMR, IR和HR-MS表征。初步的生物活性研究(MTT法)表明,7a~7g均能显著抑制人宫颈癌Hela细胞的增殖,其中5-甲氧基-4-(对乙酰氨基苯磺酰基-哌嗪基)-3-溴-2(5H)-呋喃酮(7f)的抑制活性最佳,其IC50为0.03 μM(24 h)。 相似文献
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V. Siddaiah G. Mahaboob Basha D. Sudhakar R. Srinuvasarao Y. Santosh Kumar 《合成通讯》2013,43(16):2191-2197
A simple and alternative method has been developed for the synthesis of 4-benzylidene-2-phenyl-5(4H)-oxazolones via reactions of hippuric acid with various aldehydes in the presence of 2-chloro-4,6-dimethoxy-1,3,5-triazine/N-methylmorpholine at 75 °C. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
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ZnCl_2溶液中微波辅助SnCl_4催化纤维素制备5-HMF 总被引:1,自引:0,他引:1
ZnCl溶液中微波辅助SnCl催化纤维素制备-HMF 《燃料化学学报》2017,45(3):317-322
将纤维素溶解在ZnCl_2溶液中,以SnCl_4为催化剂,微波下使纤维素降解成5-羟甲基糠醛(5-HMF)。实验考察了微波功率、纤维素的质量、ZnCl_2溶液浓度、反应时间及催化剂与纤维素物质的量比等对5-HMF产率的影响。结果表明,以SnCl_4为催化剂,在优化条件:1.0 g纤维素溶解在100 m L 70%ZnCl_2溶液中,微波功率为420 W,降解反应9 min,SnCl_4与纤维素物质的量比2∶1下,5-HMF的产率达到39.4%。 相似文献
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A novel flower-like hydrated magnesium carbonate hydroxide,Mg_5(CO_3)_4(OH)_2·4H_2O,with micro-structure composed of individual thin nano-sheets was synthesized using a facile solution route without the use of template or organic surfactant.Reaction time has an important effect on the final morphology of the product.The micro-structure and morphology of Mg_5(CO_3)_4(OH)_2·4H_2O were characterized by means of X-ray diffractometry(XRD),field-emission scanning electron microscopy(FE-SEM).Brunauer-Emmett-Teller(BET)surface areas of the samples were also measured.The probable formation mechanism of flower-like micro-structure was discussed.It was found that Mg_5(CO_3)_4(OH)_2·4H_2O with flower-like micro-structure was a novel and efficient catalyst for the synthesis of diphenyl carbonate(DPC)by transesterification of dimethyl carbonate(DMC)with phenol. 相似文献
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Four dinuclear amino acid cadmium(Ⅱ) complexes [Cd2(tren)2(dl-alaninato)](ClO4)3·H2O(Ⅰ), [Cd2(tren)2·(l-alaninato)](ClO4)3·H2O(Ⅱ), [Cd2(tren)2(dl-phenylalaninato)](ClO4)3(Ⅲ) and [Cd2(tren)2(l-phenylalaninato)]· (ClO4)3(Ⅳ), constructed from mixed ligands of tris(2-aminoethyl)amine(tren) and racemic or natural amino acids( amino acids=dl- or l-alanine, and dl- or l-phenylalanine), have been synthesized and characterized by X-ray crystallography. The structural analysis of complexes Ⅰ and Ⅲ reveals that the cadmium centers are coordinated by one tren ligand and one amino acid molecule with the unusual (N,O,O′)-bridged mode, resulting in asymmetric chromophores of CdN4O and CdN5O in complex Ⅰ, CdN4O2 and CdN5O in complex Ⅲ, respectively. The utility of the four complexes as efficient water-compatible Lewis acid catalysts for the direct aldol reaction in water was examined. The reaction proceeded smoothly to afford the corresponding β-hydroxy ketones in up to 99% yield. Moreover, the diastereoselectivity of the reaction favors the formation of the syn-isomers. 相似文献