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4‘—甲氧基—2’,7—二羟基黄烷酮的合成 总被引:3,自引:0,他引:3
2-羟基-4-甲氧基甲氰基苯乙酮与2-甲氧基甲基-4-甲氧基苯甲醚经缩合,环化,除保护基等反应合成了4’-甲氧基-2’,7-二羟基黄烷酮。 相似文献
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羟基取代的黄烷酮与NO反应, 得到了羟基邻位或对位单硝基化产物. 随着反应时间的延长, 有羟基邻位和对位双硝基化以及羟基两个邻位双硝基化产物生成. 多羟基取代的黄烷酮可以生成多硝基化产物. 相似文献
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9—羟基苯并萘酮的结构和激发态质子转移过程 总被引:1,自引:0,他引:1
用INDO系列方法对9-羟基苯并萘酮的结构和激发态质子转移过程进行了理论研究,求得基态和激发态反应的位能面、势垒和过渡态,对反应机理进行了探讨。 相似文献
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木质素催化转化制取苯、甲苯和二甲苯 总被引:1,自引:0,他引:1
对HZSM-5、HY和MCM-22三种催化剂进行了比较,其中HZSM-5催化裂解木质素制备苯、甲苯和二甲苯(BTX)的结果最优.确定了木质素催化裂解的最佳反应条件,包括反应温度、载气流速、催化剂/木质素配比.当反应温度为550-600℃,载气流速为300mL/min,催化剂/木质素配比为2时,使用HZSM-5催化裂解制备BTX的最高C产率和芳香选择性分别可达25.3%和90.9%。 相似文献
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TiO2光催化降解苯和甲苯的动力学研究 总被引:1,自引:0,他引:1
利用溶胶-凝胶法制备了粒径约为13nm、晶型为锐钛矿相和金红石相混晶的TiO2光催化剂,并利用此催化剂对挥发性有机污染物苯和甲苯进行了光催化降解研究,对不同的催化剂用量、光源、污染物的初始浓度以及氧气对光催化反应速率的影响进行了研究。结果表明,光催化降解甲苯和苯的反应均符合假一级动力学方程,光强与光催化降解甲苯的反应的速率常数之间呈指数关系,光波长对光催化降解苯的影响也很显著;随着甲苯和苯初始浓度的增加,光催化反应速率常数降低;氧气加快了光催化降解甲苯和苯的速率;对于光催化降解初始浓度为37.6μmol/L的甲苯而言,催化剂的最佳使用量为0.30g,对于光催化降解初始浓度为9.0μmol/L的苯来说,催化剂的最佳用量为0.10g。 相似文献
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胶束电动毛细管色谱法测定海洋沉积物中的苯、甲苯和二甲苯 总被引:6,自引:0,他引:6
建立了用胶束电动毛细管色谱法(MECC)对海洋沉积物中的苯、甲苯和二甲苯进行 分析测定的方法 。用45 cm(到检测窗口40 cm)×75 μm i.d.毛细管柱,以75 mmol/L SDS-2 mmol/L 四硼酸钠溶液(外加体积分数为20%的甲醇)为缓冲液(pH 9.16)。当电压为25 kV、检测 波长为200 nm时,苯、甲苯和二甲苯在20 min内得到了良好的分离。用峰面积定量,线性范 围为4~50 mg/L,相对标准偏差在6.2%以内。测得海洋沉积物中的这些苯系物的质量比范围 为3.79~17.36 μg/g。 相似文献
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Béla Imre János Halász Krisztina Frey Károly Varga Imre Kiricsi 《Reaction Kinetics and Catalysis Letters》2001,74(2):377-383
The gas-phase partial oxidation of benzene and toluene to phenol and to cresols over Fe-containing ZSM-5 zeolites prepared by various methods was studied using N2O as oxidant. Over FeZSM-5 synthesized by either isomorphous substitution or ion exchange the phenol selectivity reached nearly 100% at 573 K, however, only 25-30% cresol (mainly p-cresol) selectivity was observed in the oxidation of toluene because of the formation of benzaldehyde and benzoic acid in the fast oxidation of the methyl group. 相似文献
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P. B. Terentiev T. M. Zilberstein A. A. Borisenko V. A. Shmorgunov N. F. Piskunkova G. V. Grishina 《Chemistry of Heterocyclic Compounds》2003,39(7):885-894
It has been shown that on biotransformation of a series of 1,2,5,6-tetrahydropyridines with strains of the mycellar fungi Cunninghamella verticillata VKPM F-430, Beauveria bassiana ATCC 7159, and Penicillium simplicissimum KM-16, the culture of Cunninghamella verticillata possesses the greatest transforming activity and selectivity. With the aid of the latter practically quantitative oxidation of 1,2,5,6-tetrahydropyridines occurs into the corresponding trans-diol. The structure and spatial disposition of trans-1-benzyl-3,4-dihydroxypiperidine was demonstrated by data of chromato-mass spectrometric analysis and high resolution NMR spectra and was confirmed by comparison with an authentic sample obtained by an alternate synthesis using the oxidation of 1-benzyl-1,2,5,6-tetrahydropyridine with trifluoroperacetic acid. 相似文献
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顶空液相微萃取-气相色谱质谱法快速测定饮料中苯和甲苯 总被引:8,自引:0,他引:8
建立了顶空液相微萃取-气相色谱质谱法测定饮料中苯和甲苯的方法。在对顶空液相微萃取(head-space liquid-phase microextraction,HS-LPME)实验条件优化的基础上,确定了最佳实验条件:以1.6μL正辛醇作为有机萃取剂,在萃取温度为50℃、萃取时间为5min,搅拌速度为750r/min,液滴离萃取瓶瓶塞2.0cm的条件下,萃取4.00mLNaCl含量为4.00mol/L的样品水溶液,取0.4μL的有机萃取剂直接进样。实验结果表明,苯和甲苯的富集倍数分别为94和191,方法检出限分别为0.090μg/L和0.093μg/L,线性范围为0.5~60μg/L(r>0.999)。将该方法应用于饮料中苯和甲苯的测定,回收率为93.6%和98.0%,相对标准偏差(RSD)为3.94%和2.69%。方法简单、快速且成本低、可信度高,适用于饮料和水样中苯和甲苯的快速分析。 相似文献
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A. Villares S. Rodríguez C. Lafuente F. M. Royo M. C. López 《Journal of solution chemistry》2004,33(9):1119-1133
Experimental viscosities and the corresponding viscosity deviations for the binary mixtures of a cyclic ether (tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran, or 2,5-dimethyltetrahydrofuran) with benzene, toluene, fluorobenzene, or chlorobenzene are given at 25°C. The kinematic viscosities and the corresponding densities were measured with an uncertainty of ±10– 4 mm2-s– 1 and ±(5×10– 3) kg-m– 3, respectively. The viscosity data were correlated by the equations of Grunberg–Nissan, McAllister, and Heric. On the other hand, the results have been compared to the predictions, by the method proposed by Asfour. 相似文献
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海洋细菌对柠檬烯的生物转化及萜类产物鉴定 总被引:4,自引:0,他引:4
从南海大亚湾的海洋微生物中筛选出3株对单萜D-柠檬烯有显著生物催化转化作用的海洋细菌(Vibrio cholerae、Listonella dam sela和Vibrio alginolyticus)。以2216E为培养基,添加200mg/L的柠檬烯,在28℃,以120 r/m in摇瓶培养5 d,用乙酸乙酯提取培养液,经GC-MS分析其转化产物,结果显示,这些细菌能在柠檬烯的不同位置进行羟基化、羰基化等,并伴随有还原、水解、酯化、开环等反应,但转化能力和转化程度不同;在产物中,还检测到系列结构不同的其它萜类:包括倍半萜、二萜以及三萜等,这些萜类化合物的产生跟柠檬烯的加入有关,说明柠檬烯能影响细菌代谢产物的产生。单萜微生物转化反应操作简单、条件温和、高效率和高选择性、无毒、环境友好,能够分离发现系列新的在医药、有机合成、精细化工等领域有用的化合物,为丰富的天然单萜资源的开发与利用提供新的途径和方法。 相似文献
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Whole‐Cell Biotransformation of Benzene to Phenol Catalysed by Intracellular Cytochrome P450BM3 Activated by External Additives
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Masayuki Karasawa Joshua Kyle Stanfield Sota Yanagisawa Dr. Osami Shoji Prof. Dr. Yoshihito Watanabe 《Angewandte Chemie (International ed. in English)》2018,57(38):12264-12269
An Escherichia coli whole‐cell biocatalyst for the direct hydroxylation of benzene to phenol has been developed. By adding amino acid derivatives as decoy molecules to the culture medium, wild‐type cytochrome P450BM3 (P450BM3) expressed in E.coli can be activated and non‐native substrates hydroxylated, without supplementing with NADPH. The yield of phenol reached 59 % when N‐heptyl‐l ‐prolyl‐l ‐phenylalanine (C7‐Pro‐Phe) was employed as the decoy molecule. It was shown that decoy molecules, especially those lacking fluorination, reached the cytosol of E. coli, thus imparting in vivo catalytic activity for the oxyfunctionalisation of non‐native substrates to intracellular P450BM3. 相似文献
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Frontispiece: Whole‐Cell Biotransformation of Benzene to Phenol Catalysed by Intracellular Cytochrome P450BM3 Activated by External Additives
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Masayuki Karasawa Joshua Kyle Stanfield Sota Yanagisawa Dr. Osami Shoji Prof. Dr. Yoshihito Watanabe 《Angewandte Chemie (International ed. in English)》2018,57(38)