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《有机化学》2015,(6)
2-嘧啶氧基-N-芳基苄胺类化合物结构经过两次骨架结构优化后得到2-苯甲酰基嘧啶类化合物二次先导结构.在二次先导结构基础上,共设计并合成了36个化合物,所有化合物结构经1H NMR、13C NMR、HRMS确认,并进行了室内杀菌活性筛选,对各部位取代基进行了逐次优化.结果表明2-苯甲酰基嘧啶类化合物中R1取代基以2位卤素或烷基取代的苯环或杂环活性最好;中间苯环6位引入氟原子活性保持;嘧啶环4,6位甲氧基取代活性较好,5位甲基取代活性大大降低;羰基被还原为羟基后活性消失.其中2,3-二氯-N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)苯氧基]-N-甲基苯甲酰胺(4AHl)、2,5-二氯-N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)苯氧基]-N-甲基苯甲酰胺(4AHn)及N-[2-(4,6-二甲氧基嘧啶-2-甲酰基)-3-氟苯氧基]-N,2-二甲基苯甲酰胺(4AFd)对黄瓜白粉病的杀菌活性与对照样苯菌酮相当. 相似文献
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1.甲醇鈉對於2-乙硫醇基-4,5-二甲基-6-氯代嘧啶在甲醇溶液中生成相應的乙硫醇基嘧啶甲醚。 2.氯對於2-乙硫醇基-4,5-二甲基嘧啶衍生物(I),在水溶液中的作用是特殊的,嘧啶中的不飽和現象不被氯化反應改變而硫醇基團被氧化,形成穩定相應嘧啶碸的衍生物(II),因此製備了2-乙磺醯基-4,5-二甲基-6-甲氧基嘧啶和2-乙磺醯基-4,5-二甲基-6-氯代嘧啶. 3.2-乙硫醇-4,5-二甲基-6-甲氧基嘧啶在甲醇中進行氯化反應,現象甚複雜,並且嘧啶碸的產量很低,2-乙硫醇-4,5-二甲基-6-甲氧基嘧啶在甲醇中被氯氧化,首先形成嘧啶碸,後者並不穩定,再與氯作用形成乙磺醯氯和2-氯代-4,5-二甲基-6-甲氧基嘧啶。 4.嘧啶碸與鹼作用,乙磺醯基被羥基取代,同時在嘧啶環6位上的乙氧基保留,因此2-乙磺醯基-6-甲氧基-4,5-二甲基嘧啶與鹼作用,形成2-酮-5,6-二甲基-4-甲氧基-1,2-二氫嘧啶。 5.酒精-氨的溶液作用在氯代乙磺醯基嘧啶得到氨基-乙磺醯基嘧啶,在氯代乙磺醯基嘧啶中,嘧啶環上2位的乙磺醯基仍保留,而6位土的氯被氨基取代。 6.本文敘述了合成4,5-二甲基-2-氧代-6-氨基嘧啶(或2-酮-4-氨基-5,6-二甲基-1,2-二氫化嘧啶)的新方法。 相似文献
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3,5 -二羟基 - 7,4′-二甲氧基二氢黄酮醇 ( 1 )从 Cephalanthus spathelliferus中分离得到后 [1] ,又在H aplopappus bayahuen[2 ] 和 L annea coromandelica[3] 等植物中被发现 ,在印度一直被用于治疗象皮病、阳痿、溃疡、阴道炎、口臭、痢疾和风湿病等 . 3,5 ,7-三羟基 - 4′-甲氧基二氢黄酮醇 ( 2 )首次从 Prunusdonestica[4 ] 中分离出来后 ,又从 Salix caprea L.,Brazilian propolis中得到 .研究表明 ,该化合物具有抗菌、抗肿瘤活性 .我们用与文献 [5 ]类似的方法以 2 ,4,6-三羟基苯乙酮和茴香醛为起始原料 ,经选择性保护、缩合、… 相似文献
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设计合成了1-乙酰基-3-(2-羟基-4,6-二甲氧基苯基)-5-苯基-2-吡唑啉(4), 测试了其紫外光谱和荧光光谱, 研究了其对锌离子的选择性识别作用. 结果表明, 化合物4作为锌离子荧光探针, 受常见离子的干扰较小, 对于锌离子有着较高的选择性和较低的检出限. 相似文献
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4,6-二甲氧基-2-嘧啶重氮氨基偶氮苯的合成及其与汞(Ⅱ)的显色反应 总被引:5,自引:1,他引:4
合成了4,6-二甲氧基-2-嘧啶重氮氨基偶氮苯(DMPDAA),并研究了它与汞(Ⅱ)的显色反应。结果表明,在TritonX-100存在下,于pH 10.5 Na2B4O7-NaOH缓冲体系中,Hg(Ⅱ)与4,6-二甲氧基-2-嘧啶重氮氨基偶氮苯形成1∶4的红色配合物,其最大吸收波长位于522 nm,表观摩尔吸光系数为1.52×105L.mol-1.cm-1。Hg(Ⅱ)在0~0.80μg/mL范围内符合比尔定律。方法已用于水样中汞的测定。 相似文献
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Ce-Al2O3 catalysts prepared by co-precipitation are investigated both in NO oxidation by O2 and in selective catalytic reduction of NO by C2H2(C 2 H 2-SCR).It is found that C2H2-SCR is initiated and controlled by NO oxidation to NO 2 over Al2O3.Ce loading on Al2O3 is almost inactive for NO oxidation below 350 C,since NO2 strongly adsorbs on cerium oxide,leading to the active sites being blocked,which was characterized by temperature-programmed desorption of NO and NO 2 and Fourier transform infrared spectroscopy after NO+O 2 coadsorption over the samples.However,in the case of C2H2-SCR,Ce loading on Al 2 O 3 significantly improves the reaction by accelerating the NO oxidation step in the temperature range of 250-450 C,since the nitrate species produced by NO 2 adsorption is an active intermediate required by C2H 2-SCR. 相似文献
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在无水乙醇和乙酰丙酮混合溶液中,电解Ti金属制得前驱体Ti(OCH2CH3)4-y(acac)y,再加入ZrCl4,将上述溶液直接水解、干燥后,在450℃煅烧2 h,粉体通过X射线衍射(XRD)分析表明:纳米TiO2-ZrO2粉体呈单分散结构。扫描电子显微镜(SEM)测试表明,颗粒平均尺寸为30~40 nm。通过溶胶-凝胶法制得高活性的Ti/NanoTiO2-ZrO2修饰电极,采用循环伏安研究发现,Ti/NanoTiO2-ZrO2电极对葡萄糖氧化具有高催化活性。在NaBr电解液中,Br-在Ti/NanoTiO2-ZrO2电极表面氧化为Br2,Br2间接电氧化葡萄糖。 相似文献
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PengboJiang YongchenShang TiexinCheng YingliBi KeyingShi ShuquanWei GuolinXu KaijiZhen 《天然气化学杂志》2003,12(3):183-188
The decomposition of methane on Ni/a-Al2O3 modified by La2O3 and CeO2 with differ-ent contents has been investigated and the ralationship between methane decomposition and removal of carbon by CO2 over these catalyst has also been studied by pulse-chromatography. The catalysts were characterized by TPR and XRD. It was shown that Ni/a-Al2O3 could be promoted by adding La2O3, and the carbon species produced over this catalyst was activated and eliminated by CO2. But CeO2 would suppress the decomposition of methane over Ni crystallite. Both La2O3 and CeO2 can inhibit aggregation of the Ni particles. Decomposition of methane over the Ni-based catalysts is structure sensitive to a certain extent. 相似文献
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采用程序升温氮化法制备了Mo2N/SiO2,在此基础上负载Ni盐,制备了Ni-Mo2N/SiO2复合纳米催化剂,并考察了催化剂对四氢萘加氢的催化活性.结果表明,与Ni2Mo3N/SiO2及Ni/SiO2催化剂相比,Ni-Mo2N/SiO2复合催化剂具有较高的催化活性.采用"分离床"方法研究了Ni和Mo2N对四氢萘加氢活性的影响.通过X射线粉末衍射、透射电镜、氢吸附、元素分析和比表面积测定等技术对Ni-Mo2N/SiO2催化剂进行了表征.结果表明,与Ni/SiO2催化剂相比,Ni-Mo2N/SiO2复合催化剂中Ni的分散度并未提高;催化活性的提高归因于Ni与Mo2N在四氢萘加氢中的协同作用.氮化物的引入增加了芳烃吸附活性位的数目.提出了四氢萘在Ni-Mo2N/SiO2催化剂上的可能加氢机理. 相似文献
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Pengbo Jiang Yongchen Shang Tiexin Cheng Yingli Bi Keying Shi Shuquan Wei Guolin Xu Kaiji ZhenCollege of Chemistry Jilin University Changchun China Department of Chemistry Harbin Normal University Harbin China 《天然气化学杂志》2003,12(3)
The decomposition of methane on Ni/a-Al2O3 modified by La2O3 and CeO2 with different contents has been investigated and the ralationship between methane decomposition and removal of carbon by CO2 over these catalyst has also been studied by pulse-chromatography. The catalysts were characterized by TPR and XRD. It was shown that Ni/a-Al2O3 could be promoted by adding La2O3, and the carbon species produced over this catalyst was activated and eliminated by CO2. But CeO2 would suppress the decomposition of methane over Ni crystallite. Both La2O3 and CeO2 can inhibit aggregation of the Ni particles. Decomposition of methane over the Ni-based catalysts is structure sensitive to a certain extent. 相似文献
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反胶束体系制备负载型TiO2纳米光催化剂 总被引:7,自引:0,他引:7
在AOT/异辛烷反胶束体系中制备了粒径为2~5nm的单分散球形TiO2纳米粒子,用TEM,DSC和XRD等手段对其进行了分析;用浸渍法以小孔分子筛HZSM-5为载体制备了负载型TiO2纳米粒子,用FTIR,Langmuir及BET等手段进行了表征;用以上2种TiO2粒子作光催化剂进行了简单模拟废水处理研究,用UV-Vis光谱分析其催化效果表明,负载型TiO2纳米粒子比纯TiO2纳米粒子的光催化活性更高. 相似文献
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CeO2及Pt/CeO2催化剂上H2、O2的作用特性 总被引:12,自引:1,他引:12
采用TPD、TPR、FT-IR和TPEC等方法研究了CeO_2及Pt/CeO_2上H_2、O_2作用特性。结果表明, Pt促进CeO_2还原, 并形成高活动性氢物种。Pt的存在使吸H_2和放氢温度下阵达300 ℃。部分还原的CeO_2常温下吸附氧形成分子离子氧物种(O_2~-, O_2~(2-)), Pt的存在改变氧化铈催化剂在常温下氧吸附物种的形态, 以解离态存在。氧化铈上吸附的氧物种在升温时可部分脱附, 高于170 ℃时则转化为晶格氧。 相似文献
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Dachs A Pla-Quintana A Parella T Solà M Roglans A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(51):14493-14507
N-tosyl-linked open-chain yne-ene-yne enediynes 1 and 2 and yne-yne-ene enediynes 3 and 4 have been satisfactorily synthesised. The [2+2+2] cycloaddition process catalysed by the Wilkinson catalyst [RhCl(PPh(3))(3)] was tested with the above-mentioned substrates resulting in the production of high yields of the cycloadducts. Enediynes 1 and 2 gave standard [2+2+2] cycloaddition reactions whereas enediynes 3 and 4 suffered β-hydride elimination followed by reductive elimination of the Wilkinson catalyst to give cycloadducts, which are isomers of those that would be obtained by standard [2+2+2] cycloaddition reactions. The different reactivities of these two types of enediyne have been rationalised by density functional theory calculations. 相似文献