共查询到19条相似文献,搜索用时 156 毫秒
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以3-甲氧基苯甲醛为原料,经亨利反应、还原硝基和双键、氨基保护、傅-克酰基化、脱甲基、环合、羰基还原等反应,合成目的产物6-2-氨丙基-2,3-二氢苯并呋喃。并对硝基和双键的还原反应、傅-克酰基化和脱甲基反应的工艺条件进行了优化,得出较佳工艺条件:(1) 还原反应:反应温度40 ℃,氢气压力4.0 MPa,Raney-Ni质量为化合物2的质量的8 %,产物收率为78.6 %;(2)合成化合物6的较佳工艺条件:反应温度45 ℃,n(氯乙酰氯):n(化合物4)=1.4:1,反应时间为6 h,产物的收率为68.8 %。 相似文献
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以D-果糖为原料,经过内酯化反应、酰化、羰基还原、再次酰化4步反应合成2-C-甲基-α-D-呋喃核糖四苯甲酸酯(化合物 d),总收率为10.60%。采用1H-NMR、13C-NMR和MS等方法对中间产物和目标产物进行了结构表征。在2-C-甲基-D-核糖酸-1,4-内酯(a)的合成中,结合反应条件确定了最佳原料为D-果糖和氧化钙;通过对还原剂剂硼氢化钠﹑四氢化铝锂和红铝的比较,得出红铝为中间体2,3,5-三苯甲酰氧基-2-C-甲基-βD-呋喃核糖(c)合成的较优还原剂,还原收率可达96.20%;通过单因素考察确定三乙胺作为酰化反应的缚酸剂,酰化收率可达75.84%。 相似文献
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以1,5-二氯-2,4-二硝基苯(DCDNB)为原料,经烷氧基化和催化加氢还原反应合成4,6-二乙氧基间苯二胺(DEDAB),并探索了其影响因素。结果表明合成中间体1,5-二乙氧基-2,4-二硝基苯(DEDNB)的较佳条件为:n(DCDNB)∶n(NaOH)∶n(无水C2H5OH)=1∶4∶30,室温下反应7 h,收率96.43%,HPLC纯度99.74%;产品DEDAB的较优合成工艺条件为:n(DEDNB)∶n(无水C2H5OH)= 1∶44,w(10%Pd/C)/w(DEDNB)= 10%,反应时间7 h,反应温度110 ℃,氢气压力1.5 MPa,收率95.42%,HPLC纯度98.87%。产品及中间体结构经1H NMR、MS 和FTIR分析表征确认。 相似文献
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以5-氟-2-硝基苯胺为起始原料,经亲核取代、氢化还原和酰化反应合成了瑞替加滨,并对反应工艺条件进行了优化。中间产物2-氨基-4-(4-氟苄胺基)硝基苯的优化条件为:以三乙胺为缚酸剂,n(5-氟-2-硝基苯胺)∶n(4-氟苄胺)∶n(三乙胺)=1.0∶1.2∶1.3,反应温度为90℃,反应时间为8 h,得中间产物,收率可达92.94%。瑞替加滨合成的优化条件为:以四氢呋喃为溶剂,钯碳(Pd/C,5%)为催化剂,氢压为101.325 kPa,反应温度为35℃,氢化还原反应3 h后,在15℃下滴加盐酸溶液后继续氢化还原反应,此后不经分离与氯甲酸乙酯直接进行酰化反应得粗品,粗品经乙醇/正己烷混合溶剂精制,得到目标产物瑞替加滨,总收率43.09%,质量分数可达99.9%(HPLC),其化学结构经元素分析、1H NMR、13C NMR和ESI-MS确证。该合成工艺方法操作简单,稳定可靠,原料易得,催化剂可以回收再用,有效地降低了生产成本,有利于工业化生产。 相似文献
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A simple, regioselective, environmentally cleaner and economical method for the electrochemical preparation of benzyl bromide from toluene by two-phase electrolysis is reported. Electrochemical bromination of toluene is carried out in an undivided cell at 0 °C and the process parameters are studied and optimized. In this method 94% yield and 98% conversion is achieved. 相似文献
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Efficient Synthesis of Octacosanol Linoleate Catalyzed by Ionic Liquid and Its Structure Characterization
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Wen-Sen He Qiao Liu Huan Yu Xiao-Jing Si Jin-Ku Zhang 《Journal of the American Oil Chemists' Society》2016,93(4):509-517
Octacosanol, as the major active policosanol, has attracted much attention due to the potential beneficial effects for human health. However, free octacosanol has a high melting point, poor oil solubility and low bioavailability, which greatly restricts its practical application. In this study, we report a highly efficient method for an ionic liquids (IL)‐catalyzed synthesis of octacosanol ester by direct esterification with linoleic acid. The synthesized product was purified, subsequently characterized by FT‐IR, MS and NMR and finally confirmed to be octacosanol linoleate. The reaction parameters were investigated and the conversion reached 91.3 ± 4.8 % under the optimum conditions: IL 1‐butylsulfonate‐3‐methylimidazolium hydrogen sulfate ([BSO3HMim][HSO4]) as catalyst, IL dose 1.5 % (related to the mass of both reactants), 1:1 molar ratio of octacosanol to linoleic acid, 80 °C, and 1 h. The melting point and oil solubility of octacosanol were greatly improved by esterification with linoleic acid, facilitating the incorporation into a variety of oil‐based systems. 相似文献