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以9-苯基咔唑为原料,以二氯甲烷为辅助溶剂,利用水相法经N-溴代丁二酰亚胺(NBS)亲电取代反应合成目标产物3,6-二溴-9-苯基-9H-咔唑。在n(9-苯基咔唑)∶n(NBS)=1.00∶2.10,反应温度25℃,反应时间120 min的优化反应条件下,目标产物3,6-二溴-9-苯基-9H-咔唑的收率为90.6%。 相似文献
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以12-羟基硬脂酸和3种不同类型的天然氨基酸为原料,采用N,N′-二环己基碳酰亚胺(DCC)和N-羟基丁二酰亚胺(NHS)作为偶合剂,合成了3种具有代表性的N-12-羟基硬脂酰氨基酸(酸性、中性和碱性)表面活性剂。首先,12-羟基硬脂酸和N-羟基丁二酰亚胺反应制得N-羟基琥珀酰亚胺12-羟基硬脂酸酯(产率85%以上),然后将后者与氨基酸进行缩合反应得到了N-12-羟基硬脂酰氨基酸表面活性剂。其较佳合成工艺条件为:N-羟基琥珀酰亚胺12-羟基硬脂酸酯与氨基酸摩尔比为1∶1,室温反应,反应时间不少于4 h,以丙酮与水体积比1∶1为混合溶剂,产率达到80%。利用IR、元素分析和1HNMR对所得产物进行表征,确定了产物结构。 相似文献
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The selective and successive precipitation resulting from the biological solubilization (Thiobacillus ferrooxidans) of sewage sludge metals was studied. At the same time, theoretical diagrams representing the solubility of hydroxides and metal carbonates (Ca, Mg, Fe, Al, Cu, Zn, Ni, Cd, Mn) and their complexes are compared to the experimental values. The pH was progressively increased by means of Ca(OH)2- The iron hydroxide precipitate, which was the least contaminated, was obtained at pH of 3.5. The theoretical pH's for acceptable metal precipitation were identified as: Fe+3 at pH 3.2, Al+3 at pH 4.7, Cu+2 at pH 6.9, Zn+2 at pH 8.15, Ni+2 at pH 8.4 and Mn+2 at pH 9.1, and were closed to theoretical values. The hydroxide ion controls Ca, Mg and Cu solubilities. A precipitate with about 20% of Cu can be obtained at a pH of 7 after iron hydroxide was precipitated. Recovery of other metals than iron is thus possible. 相似文献
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采用一锅煮合成法,以红霉素肟为原料、甲醇为溶剂,将红霉素肟贝克曼重排反应和还原反应在一个容器中进行,得到阿奇霉素前体9-脱氧-9a-氮杂-9a-同型红霉素(AZA).红霉素肟经贝克曼重排反应结束后,直接在反应液中加入硼氢化钠继续进行还原反应,得到的目标产物的收率为98%,纯度为90.5%. 相似文献
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In the present paper the authors propose a pattern of calculation permitting to predict the thermal evolution of a gas-fluidized system, which is mechanically stirred and subjected to abrupt fluctuations of the speed of the agitator. The two following cases are studied:
- a full-fluidized system.
- a partly-fluidized system involving a dense portion of wall layer.
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The three parameters of a modified Clausius state equation have been generalized with a view to calculating thermodynamic properties of saturated pure substances, from the normal boiling temperature to the critical one. The method described in the paper, which only requires the knowledge of the characteristic properties of the pure substances (Tc, Pc, Zc, ω) has been tested on 28 different compounds (saturated and unsaturated hydrocarbons, simple and polar molecules). The results obtained show that the state equation proposed correctly describes the liquid-vapour equilibrium (saturation vapour pressure and vaporization enthalpy) and moreover provides a satisfactory representation of the saturated liquid condition. 相似文献