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81.
以氯乙酸甲酯、4-苯氧基苯酚为原料,在无水碳酸钾存在下,N,N-二甲基甲酰胺(DMF)为溶剂,制备了中间体2-(4-苯氧基苯氧基)乙酸甲酯(Ⅰ),进而,中间体(Ⅰ)和二甲胺反应。得到目的产物N,N-二甲基-2-(4-苯氧基苯氧基)乙酰胺(Ⅱ)。考察了反应温度、反应时间、物料投料比对目的产物(Ⅱ)收率的影响,从而确定了合成工艺条件为:反应温度15~20°C;反应时间3.5~4 h;物料投料比n(Ⅰ)∶n(二甲胺)=1.0∶1.4。在此条件下,N,N-二甲基-2-(4-苯氧基苯氧基)乙酰胺的收率达80%以上。化合物的结构经IR1、H NMR和元素分析进行了表征。 相似文献
82.
BACKGROUND: Trimethylamine oxide (TMAO) in squid is demethylated to dimethylamine (DMA) and formaldehyde (FA) during storage and processing. This study examined the effects of thermal processing and various chemical substances on FA and DMA formation in squid. RESULTS: The thermal conversion of TMAO was assessed by analysing four squid and four gadoid fish species, which revealed that FA, DMA and trimethylamine (TMA) were gradually produced in squid, whereas TMA increased and FA decreased in gadoid fish. A significant increase in both FA and DMA levels was observed in the supernatant of jumbo squid with increased heating temperature and extended heating time at pH 6–7. Ferrous chloride combined with cysteine and/or ascorbate had a significantly positive effect on FA formation in the heated supernatant of jumbo squid. No significant difference was observed in the levels of Cu and Fe in squid and gadoid fish. The capability of Fe2+ to promote the formation of FA and DMA was not completely attributable to its reducing power in squid. CONCLUSION: Non‐enzymatic decomposition of TMAO was a key pathway during the thermal processing of jumbo squid, and Fe2+ was a crucial activator in the formation of FA and DMA. Copyright © 2012 Society of Chemical Industry 相似文献
83.
Uzi Landman Bokwon Yoon Chun Zhang Ueli Heiz Matthias Arenz 《Topics in Catalysis》2007,44(1-2):145-158
Focusing on size-selected gold clusters consisting of up to 20 atoms, that is, in the size regime where properties cannot
be obtained from those of the bulk material through scaling considerations, we discuss the current state of understanding
pertaining to various factors that control the reactivity and catalytic activity of such nanostructures, using the CO oxidation
reaction catalyzed by the gold nanoclusters adsorbed on MgO as a paradigm. These factors include the role of the metal-oxide
support and its defects, the charge state of the cluster, structural fluxionality of the clusters, electronic size effects,
the effect of an underlying metal support on the dimensionality, charging and chemical reactivity of gold nanoclusters adsorbed
on the metal-supported metal-oxide, and the promotional effect of water. We show that through joined experimental and first-principles
quantum mechanical calculations and simulations, a detailed picture of the reaction mechanism emerges. 相似文献
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86.
Zinc oxide (ZnO) is a versatile material for different commercial applications such as transparent electrodes, piezoelectric
devices, varistors, SAW devices etc because of its high piezoelectric coupling, greater stability of its hexagonal phase and
its pyroelectric property. In fact, ZnO is a potential material for gas sensor applications. Good quality ZnO films were deposited
on glass and quartz substrates by a novel CVD technique using zinc acetate as the starting solution. X-ray diffraction confirmed
the crystallinity of the zinc oxide film and SEM study revealed uniform deposition of fine grains. Undoped ZnO films were
used for detection of dimethylamine (DMA) and H2 at different temperatures by recording the change in resistivity of the film in presence of the test gases. The response
was faster and the sensitivity was higher compared to the earlier reported ZnO based sensors developed in our laboratory.
The main objective of this work was to study the selectivity of the ZnO film for a particular gas in presence of the others.
The operating temperature was found to play a key role in the selectivity of such sensors. 相似文献
87.
间硝基甲苯与双氧水、氢溴酸在AIBN作用下,生成间硝基一溴苄和二溴苄,再经DMSO、二甲胺氧化水解生成间硝基苯甲醛。研究了溴化、氧化水解反应的影响因素,优化了反应条件。结果表明,溴化反应较佳的条件为:溴化温度60℃,溴化时间4 h,n(间硝基甲苯)∶n(氢溴酸)∶n(双氧水)=1∶2.5∶2.5,AIBN用量0.8 g;氧化水解反应较佳的条件为:氧化温度105℃,保温时间8 h,水解温度60℃,水解时间1 h。在该条件下,间硝基苯甲醛收率达58.6%,色谱纯度达99.1%。通过IR和1HNMR对产物结构进行了表征。 相似文献
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89.
Croswel Aguilar Rafael García Gabriela Soto-Garrido Renán Arraigada 《Topics in Catalysis》2005,33(1-4):201-206
The catalytic wet air oxidation (CWAO) of methyl and dimethylamines was studied. A commercial peach stones activated carbon and its oxidized and reduced forms were used as catalysts. The observed catalytic behavior is related to the presence of oxygenated surface functional groups on the activated carbons. The N-compounds were selectively oxidized to nitrogen, water and carbon dioxide using these activated carbon catalysts. It is proposed that the quinonic surface groups are responsible for the selective catalytic oxidation of these amines. Carboxylic, lactonic and anhydride groups strongly adsorb the amine compounds producing inhibition of the catalytic activity of the activated carbon in the CWAO process. 相似文献
90.
一氯甲苯和氰化钠在催化剂作用下合成苯乙腈,传统工艺使用二甲胺作催化剂。采用LD催化剂,优化了工艺条件,与使用二甲胺催化剂相比提高了产品含量和收率。 相似文献