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研究了以无水碳酸钠为催化剂,红霉素肟与甲氧基乙氧基氯甲醚(MEMC)为原料,一步合成罗红霉素的实验过程。探讨了催化剂用量、反应物用量、反应溶剂选择、结晶方法等对反应的影响,在最佳条件下,罗红霉素的合成摩尔收率超过90%。 相似文献
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由3-氯-1-丙醇法合成3-甲氧基-1-丙醇确定的较佳工艺条件为:甲醇钠/3-氯-1-丙醇摩尔比=1.4~1.8,甲醇钠的甲醇溶液质量分数=27%~30%,滴加温度及反应温度均为70℃,滴加时间为1h,反应时间为5h,并确定了中和方法及精馏提纯条件。产品收率在85%以上,较文献报道产品收率有明显提高。 相似文献
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以3-氯丙酰氯、氯苯、三氯化铝、浓硫酸为原料合成5-氯-2,3-二氢-1-茚酮,对影响反应的主要因素进行了研究,优化了条件,优化后的反应条件为:氯代酮合成:n(三氯化铝)∶n(氯苯)∶n(3-氯丙酰氯)=1.1∶4∶1,滴加温度为5℃,滴加时间2h,保温温度60℃,保温时间3h;5-氯茚酮合成:搅拌速度小于100r/min,n(H2SO4)∶n(氯代酮)=36.8∶1,滴加时间4h,溶剂为石油醚(90-120℃)。此工艺原料价廉易得,产品纯度高,总收率达50.6%,产品纯度达98%。 相似文献
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《山东化工》2015,(18)
通过两种方案合成N-丙烯酰吗啉(ACMO)。(1)以丙烯酸、三氯化磷为原料合成丙烯酰氯,再与吗啉酰基化反应制备ACMO。最优条件:n(丙烯酸):n(三氯化磷)=2.32:1.00,温度45℃,时间5 h;n(丙烯酰氯):n(三乙胺):n(吗啉)=1.00:1.00:1.05,温度-5~0℃,时间7 h。(2)丙烯酸甲酯与甲醇先加成,再与吗啉进行酯的胺解与裂解反应。最优条件依次:n(丙烯酸甲酯):n(甲醇)=1:1.15(甲醇钠0.045),温度55℃,滴加时间6 h,总时间12 h;n(甲氧基丙酸甲酯):n(吗啉)=1:1.3(氢氧化钠0.04),温度145℃,时间18 h;裂解以吩噻嗪/氯化亚铜为复配阻聚剂(总反应量的0.5%),温度185℃,时间10 h。通过气相色谱分析(GC)及双键含量测试对以上合成的ACMO进行结构表征,GC纯度(纯化前)98.0%左右。以上两工艺的合成研究对ACMO工业化具有重要的指导意义。 相似文献
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Liangfeng Sun Su‐Seng Pang Arthur M. Sterling Ioan I. Negulescu Michael A. Stubblefield 《应用聚合物科学杂志》2002,86(8):1911-1923
The dynamic curing process was studied by using differential scanning calorimetry (DSC) and modeled by two methods. One was based on the Kissinger and Ozawa approach, in which the activation energy was taken as a constant for all the heating rates. The whole curing process was modeled with two cure reactions. Reaction 1 exhibited the behavior of the autocatalytic reaction, whereas Reaction 2 was the nth order reaction. The effect of heating rate on the preexponential factor A1 of Reaction 1 was apparent. As the heating rate increased, the A1 decreased. There was no significant effect of heating rate on the preexponential factor A2 of Reaction 2 and the reaction orders for both reactions. The calculated results showed that the contributions of these two reactions to the total curing process were very different and changed with the heating rate. Except in the early cure stage, the calculated total degree of cure agreed well with the experimental data. Another method was based on the Borchardt and Daniels kinetic approach, where the activation energy of the cure reaction at each heating rate was determined separately. The whole curing process was modeled with one autocatalytic reaction. The fitting results showed that both preexponential factor and activation energy increased with the increment of the heating rate. As in the first method, the effect of heating rate on the orders of reaction was very small. The calculated results agreed well with experimental values in the early cure stage. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1911–1923, 2002 相似文献
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以红霉素6,9-亚胺醚为原料,采用硼氢化钾还原,以简单方法制备结晶9-脱氧-9a-氮杂-9a-同型红霉素A水合物,然后再将其甲基化得到阿奇霉素,收率为92%,并确定了还原反应的温度、时间、以及甲基化水解反应的试剂和催化剂。 相似文献
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以甲苯为溶剂,四氢糠醇、氢氧化钠、溴乙烷和顺丁烯二酸酐为原料,制备四氢糠醇乙醚。考察了原料配比、温度、时间等对收率和含量的影响,优化条件为n(四氢糠醇):n(氢氧化钠):n(溴乙烷)=1:1:1-1.2;n(再精制时残余四氢糠醇):n(顺丁烯二酸酐)=1∶1.2,在合成四氢糠醇钠盐时,反应温度115℃,反应时间4-5h;在反应脱除残余四氢糠醇时,反应温度60-70℃,反应时间6h,四氢糠醇乙醚总收率达75%,纯度99%。制备的四氢糠醇乙醚能满足阴离聚合合成高乙烯基含量的SSBR的要求。 相似文献
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2,3-二甲氧基-5-甲基-1,4-苯醌的合成 总被引:2,自引:0,他引:2
以3,4,5-三甲氧基甲苯(TMT)为原料,先由V ilsm e ier-Haack反应合成6-甲基-2,3,4-三甲氧基苯甲醛,然后在对甲基苯磺酸催化下经Dak in反应将其氧化为6-甲基-2,3,4-三甲氧基苯酚,最后用重铬酸钠催化氧化合成了辅酶Q0,过程总收率达到72.3%。经正交实验得V ilsm e ier-Haack反应的最佳工艺为:n(TMT)∶n(POC l3)∶n(DMF)=1∶1.8∶2.2,反应温度70℃,反应时间7 h。在此工艺条件下,此步反应收率可达93.2%,w(6-甲基-2,3,4-三甲氧基苯甲醛)=98.5%;在Dakin反应中,以w(H2O2)=30%为氧化剂,30℃为最佳反应温度,反应时间1.5 h。 相似文献