共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
尼莫地平的合成以双乙烯酮(DK)、乙二醇独甲醇,异丙醇,间硝基苯甲醛为基本原料,经缩合,氨化,Michael加成反应,环合等反应制得。反应条件温和,副反应少,通过对少Michael加成和环合等反应进行工艺改进,使环合一步的收主经为83.72%,较文献收率高2.72%。 相似文献
4.
尼伐地平属于第二代二氢吡啶类钙离子拮抗剂 ,其与Ca2 + 通道特异部位的结合力比硝苯地平强 10倍 ,作用持续时间较之长 2~ 3倍 ,血药浓度较为平稳 ,良好的降压作用能维持 2 4h以上。因此 ,尼伐地平是安全、有效的首选高血压治疗药物 ,其应用前景十分广阔 ,市场潜力十分巨大。 相似文献
5.
6.
7.
8.
以乙酰乙酸甲氧基乙基酯、乙酰乙酸肉桂醇酯为起始原料,经中间体3-氨基巴豆酸肉桂醇酯,通过Aldol缩合、Hantzsch环合反应,合成出了钙离子拮抗剂西尼地平。该合成工艺安全可行,操作简单,适合工业化生产。 相似文献
9.
以西尼地平为起始原料,活化MnO2为氧化剂,一步法制备了2,6-二甲基-4-(3-硝基苯基)吡啶-3,5-二甲酸3-(2-甲氧基)乙酯5-(3-苯基)-2(E)-丙烯酯(记为西尼地平杂质Ⅰ).经实验优化,制备西尼地平杂质Ⅰ的最适宜条件为:m(西尼地平):m(MnO2)=1.00:1.24,甲苯为溶剂,105℃下反应1 h.反应得到西尼地平杂质Ⅰ收率为92.3%,经高效液相色谱面积归一化法检测后,纯度达到99.2%.产物结构经HRMS,1HNMR、13CNMR以及FTIR进行确认.该反应实现了西尼地平绿色高效直接转化西尼地平杂质Ⅰ. 相似文献
10.
11.
利用化学方法研究脲醛树脂的结构 总被引:2,自引:0,他引:2
脲醛树脂的结构随反应条件的变化会产生较大的变异。深入了解脲醛树脂的化学结构,对充分发挥其使用性能具有决定性意义。本文采用化学方法对四种工艺条件下合成的脲醛树脂进行相关分子含量测定,结合实验结果和合成工艺作了结构分析,并对比分析了衰减全反射红外光谱图。两种分析手段得出了一致的结论,说明化学方法完全可以用于脲醛树脂的结构表征。为相关的生产和应用人员掌握脲醛树脂的结构,提供了一种简单可行的方法。 相似文献
12.
杀鼠新化学结构的IR和13C-NMR分析 总被引:3,自引:0,他引:3
用IR光谱和13CNMR谱对新型杀鼠剂杀鼠新的化学结构进行了分析,得出杀鼠新是以双甲苯敌鼠烯醇式结构的铵盐为主,还有一小部分酮式结构的双甲苯敌鼠存在.分析证实,在弱碱的作用下,得不到完全的双甲苯敌鼠铵盐. 相似文献
13.
S. I. Futko 《Combustion, Explosion, and Shock Waves》2003,39(3):261-269
On the basis of skeleton diagrams and sensitivity analysis, the structure of the heat-release region, special features of formation of radicals, and methane-oxidation dynamics under conditions of filtration combustion of an ultralean methane–air mixture are considered in detail. It is shown that the exothermal region consists of two consecutive peaks, the first one due to oxidation of hydrocarbons and hydrogen by OH radicals and the other due to the CO oxidation reaction. Several specific regions are identified in the wave, depending on the prevailing reactions of branching of radical chains. The main chain mechanism of formation of radicals is the reaction CH3 + O2 = CH3O + O in the region of low temperatures, the reaction HO2 + CH3 = CH3O + OH in the transitional region, and the reaction H +O2 = O + OH in the region of high temperatures. Two former regions correspond to the preheating zone, and the latter corresponds to the reaction zone of the wave of filtration combustion of gases. 相似文献
14.
对采用一次高真空蒸馏 ,粉状活性炭吸附得到的异山梨醇成品 ,进行了紫外光谱、红外光谱、质谱、核磁共振氢谱和碳谱测定。经波谱解析确证了异山梨醇的化学结构为 1,4;3 ,6 二脱水 D 山梨醇 相似文献
15.
16.
文章运用MOPAC半经验量化程序,对部分染料分子结构进行计算,然后将结果和事实相对照与比较,从而分析染料分子结构与颜色的关系,并从中总结出一些规律。 相似文献
17.
通过便携式能量色散型X射线荧光、X射线衍射和激光Raman光谱等无损分析技术研究了11块天然玻璃样品的化学成分、结构和物相。结果表明:除两件样品(B1和H3)外,其它样品均为玻璃态,主要化学成分为SiO2与Al2O3。通过化学成分分析可以区分玻陨石和黑曜石样品,玻陨石中铁与碱土金属含量比黑曜石高,而碱金属含量比黑曜石低。激光Raman光谱测试表明:样品在470 cm–1附近有玻璃态特征的弥散包络峰,应为含有6个[SiO4]组成的变形环状结构单元。 相似文献
18.
The structure of premixed ethyl butanoate/O2/Ar flames stabilized on a flat burner at atmospheric pressure was studied by molecular beam mass spectrometry. Mole fraction profiles of the reactants, stable products, and major intermediates and temperature profiles were obtained in flames of stoichiometric (φ = 1) and rich (φ = 1.5) combustible mixtures. Experimental data are analyzed and compared with previously obtained experimental and numerical data for methyl pentanoate flames. The structure of ethyl butanoate flames is simulated using a detailed literature chemical-kinetic mechanism for the oxidation of fatty acid esters. The experimental profiles are compared with the simulated ones, and the conversion pathways of ethyl butanoate are analyzed. Based on a comparative analysis of experimental and simulated data, the main shortcomings of the model presented in the literature are identified and possible ways are proposed to improve the model. The decomposition of ethyl butanoate and methyl pentanoate are discussed based on an analysis of their conversion pathways; similarities and characteristic differences between their oxidation processes due to the structural differences of the molecules of the fuels are outlined. 相似文献
19.
The Chemical Structure of UF Resins 总被引:6,自引:0,他引:6
Richard M. Rammon William E. Johns James Magnuson A. Keith Dunker 《The Journal of Adhesion》1986,19(2):115-135
The structure of urea-formaldehyde (UF) resin was studied in light of the influence of various synthesis parameters on the chemical structure of the resulting resin solutions. The structural variability was analyzed by 13C nuclear magnetic resonance spectroscopy (NMR). Using appropriate pulse techniques, quantitative determination of the proportion of various functional groups was obtained.
The parameters of formaldehyde/urea mole ratio, pH control, extent of reaction, and concentration of reactants were shown to affect the final resin structure. Variation of these parameters influenced the extent of branching, the rate of condensation, and the proportion of di-methylene ethers and cyclic uron structures. 相似文献
The parameters of formaldehyde/urea mole ratio, pH control, extent of reaction, and concentration of reactants were shown to affect the final resin structure. Variation of these parameters influenced the extent of branching, the rate of condensation, and the proportion of di-methylene ethers and cyclic uron structures. 相似文献