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排序方式: 共有391条查询结果,搜索用时 31 毫秒
101.
M. R. P. Kurup E. Lukose K. Muraleedharan 《Journal of Thermal Analysis and Calorimetry》2000,59(3):815-825
Iron(III) complexes of o-vanillin oxime have been synthesized and characterized by different physicochemical techniques. The complexes containing
thiocyanate, iodide and sulphate ionshave been subjected to non-isothermal decomposition studies in N2 using TGand DTG techniques. The kinetic parameters for both stages of decomposition of these complexes were evaluated by
weighted least-squares method using the general approach as well as the Coats–Redfern and Horowitz–Metzger equations. The
results indicate that the values of kinetic parameters obtained by these three different approaches agree well.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
102.
In the presence of pyridine, 3-aryl-4-formylsydnone (II) reacts with hydroxyl-amine hydrochloride to produce 3-aryl-4-formylsydnone oxime (III). This reaction was performed in ethanol solution with reflux or at room temperature; the latter procedure gave an excellent yield (74-98%) and high purity. (III) reacts in acetic anhydride at room temperature to give 3-aryl-4-formylsydnone oxime O-acetate (IV). A convenient method for the synthesis of 3-aryl-4-cyanosydnone (V) is to dehydrate (III) with acetic anhydride at reflux. When (IV) was refluxed with acetic anhydride, (V) was similarly obtained. Another convenient method to prepare (V) from (III), dehydration with thionyl chloride at room temperature, was also investigated. 相似文献
103.
Preparation of some novel spiro-oxazolidines related to 3, which is known to posses anorectic and antidepressant activity, via 1,3-APT-1,3-DC cascades of the oxime of benzobicyclo[3.3.1]non-5-en-9-one 1 is described. Substrate 1 allows the influence of the two bridges on the cascade to be assessed with respect to the configuration of the nitrone that is generated and the facial selectivity of the subsequent cycloaddition. 相似文献
104.
105.
B. S. Fedorov N. L. Gotovina V. V. Arakcheeva R. F. Trofimova L. O. Atovmyan 《Russian Chemical Bulletin》1996,45(5):1157-1161
A novel reaction of the sodium salt of 2-nitroethanol in aqueous ammonia resulted in the sodium salt of 2-oxo-3-hydroxypropionic acid oxime (1) has been found. Bromination of1 affords 2-bromo-2-nitropropane-1,3-diol (2) with a previously unknown molecular conformation. The formation mechanisms of compounds1 and2 were suggested. X-ray analysis of products1,2 and that of the model compound, 2,2-dinitropropane-1,3-diol, was performed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1217–1221, May, 1996. 相似文献
106.
4—氯苯基环丙基酮肟—O—(3—苯氧基苄基)醚的新合成途径 总被引:1,自引:0,他引:1
采用农药厂副产物三乙基-3-苯氧基苄基氧化铵与4-氯苯基环丙基酮肟在碱性的条件下反应合成4-氯苯基环丙基酮肟-O-(3-苯氧基苄基)醚,产率80%。 相似文献
107.
建立了柱后光化学衍生荧光检测高效液相色谱法测定2种新型肟醚类农药(硫肟醚、HNPC-A2005)的方法。在优化的流动相配比(V甲醇∶V水=80∶20)及流速(1.0mL/min)条件下,用配备ZORBAXSB-C18色谱柱、自制的光化学反应器及荧光检测器的高效液相色谱仪对待测组分进行分离和测定。在最佳条件下,方法的检出限分别为0.056mg/L(硫肟醚)、0.036mg/L(HNPC-A2005);线性范围为0.090~5.0mg/L;相对标准偏差(0.1mg/L,n=8)分别为3.5%(硫肟醚)、0.8%(HNPC-A2005)。 相似文献
108.
红霉素肟及相关化合物的高效液相色谱分析 总被引:8,自引:0,他引:8
探讨和优化红霉素肟及相关化合物的HPLC分析色谱条件 ,紫外检测波长为 2 0 5nm ,使用Hitachi色谱系统 ,ODS C1 8色谱柱 (1 5 0mm× 4mmI.D .) ,控制流速 1mL min ,流动相为磷酸二氢钾 乙腈 (65∶3 5 ) ,明确指认了红霉素肟合成中主要成分的Z、E异构体 ,红霉素 6,9 半缩酮 ,红霉素 6,9 9,1 2螺缩酮的位置 ,同时对红霉素A ,红霉素C的吸收峰位置也进行了辨析 ,线性相关性良好。对红霉素肟及相关化合物的详细HPLC解析 ,为有效改进红霉素肟的合成工艺起到指导作用 相似文献
109.
环己酮肟在改性氧化锆催化剂上的Beckmann重排反应Ⅲ.B_2O_3对ZrO_2的改性效应 总被引:1,自引:0,他引:1
采用IR和XRD技术研究了B2O3/ZrO2催化剂的结构性质,用ICP-MS测定了样品中B2O3的含量,通过Hammet指示剂正丁胺滴定法测定了B2O3/ZrO2系列催化剂的表面酸性;研究了载体预处理温度对样品表面酸性和结构的影响,以及B2O3含量对样品催化性能的影响;比较了B2O3负载于ZrO2,Al2O3,SiO2,TiO2,MgO和HZSM-5上催化活性和目的产物选择性的差异,讨论了B2O3/ZrO2催化剂在气固相Beckmann重排反应中的作用特点 相似文献
110.
An efficient and reusable heterogeneous catalyst with oxime‐derived palladacycle immobilized in an ionic liquid brush has been synthesized and an environmentally‐friendly procedure have been developed for coupling aryl iodides and bromides with acrylic acid. These reactions were conducted in neat water under aerobic conditions with water‐insoluble or even solid aryl halides and they proceeded smoothly and cleanly without any organic co‐solvent or other additives. The ionic liquid brush could be easily recovered and reused at least five times without significant loss of activity. The protocol has the advantages of excellent yields, environmental friendliness, and catalyst recyclability. 相似文献