共查询到20条相似文献,搜索用时 93 毫秒
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乙醛酸法合成香兰素缩合反应的催化研究 总被引:5,自引:0,他引:5
以愈创木酚和乙醛酸为原料,通过催化缩合反应合成香兰素的中间体3-甲氧基-4-羟基扁桃酸(MHMA)。研究了不同种类催化剂对愈创木酚-乙醛酸法合成香兰素的缩舍反应的影响。结果表明:1^#催化剂对愈创木酚和乙醛酸缩合反应的活性较高,乙醛酸的转化率可达95%以上,3-甲氧基-4-羟基扁桃酸的选择性达85%。 相似文献
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利用松树杂酚油提取物合成香兰素新工艺 总被引:1,自引:0,他引:1
目前 ,全球香兰素需求量约 1 5万t/a ,且每年以 5 %的速度递增。生产方法主要有愈创木酚法、木质素法、黄樟素法、丁香酚法、甲酚法和微生物法等。本文以松树杂酚油为原料提取 4 甲基愈创木酚 ,然后利用 4 甲基愈创木酚一步氧化合成香兰素。该新工艺与现有香兰素生产工艺相比较 ,具有原料来源充足、工艺简单、产品选择性高、三废排放少的特点 ,是一条绿色化学工艺。 相似文献
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乙基香兰素合成方法研究进展 总被引:1,自引:0,他引:1
介绍了乙基香兰素的性质、用途和生产状况,分别对原儿茶醛法、黄樟油素法、乙基愈创木酚法、对羟基苯甲醛法、对甲苯酚法、邻苯二酚法合成乙基香兰素的优劣进行了评述,并提出了以邻苯二酚为原料合成乙基香兰素的路线,展望了生物技术合成乙基香兰素的应用前景。 相似文献
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3-乙氧基-4-羟基扁桃酸的合成研究 总被引:4,自引:1,他引:4
以邻羟基苯乙醚 (乙基愈创木酚 )和乙醛酸为原料 ,在碱性条件下发生缩合反应 ,合成了 3 乙氧基 4 羟基扁桃酸 ,此物质是以乙醛酸法制备乙基香兰素的中间体。通过对反应条件的优化发现 ,此合成反应的最佳反应温度为 5 0~ 60℃ ,最佳碱浓度范围为 2 0~ 4 4M ,最佳缩合反应时间为 3 5~ 8h。同时采用碱溶液的部分滴加方式 ,可使缩合反应在较短的时间内完成 ,收率达 80 %以上 ,未反应的乙基愈创木酚可以回收。 相似文献
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Cellulosic polymers were tested by measuring their permeabilities of propane and propylene. High permeabilities and selectivities were obtained with ethyl cellulose membranes. Hollow fibers coated with ethyl cellulose were made through a solution coating method. Microporous polypropylene hollow fibers were used as base material. A dense layer of ethyl cellulose about 6–10 μm in thickness was formed on the microporous hollow fiber. The performance of a coated membrane column was tested for the separation of propane and propylene mixture gas. It was concluded that ethyl cellulose membranes have a good potential for the separation of olefins form saturated hydrocarbons. 相似文献
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Teresa P. Icenhour Frances M. Van Dolah 《Journal of the American Oil Chemists' Society》1991,68(9):659-661
A rapid, quantitative gas Chromatographic method is described for quantitating the phenolic antioxidant,tert- butyl hydroquinone (TBHQ), in fish oil ethyl esters. The procedure entails silyl derivatization of TBHQ in an acetonitrile
solution of ethyl esters followed by capillary gas chromatography (GC) analysis with an internal standard method of quantitation.
Average recoveries of spiked samples were 98% at the legal limit of .02% (200 μg/g). The method can accurately determine as
little as 20 μ/g of TBHQ in ethyl esters of fish oil. The technique has been applied to ethyl esters of vegetable oils with
equal success. 相似文献
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在汽液双循环玻璃平衡釜中测定3-羟基丁酸乙酯、巴豆酸乙酯、乙醇的二元及三元体系的等压汽液平衡数据,用积分法对其进行了热力学一致性检验.回归实验数据得到3-羟基丁酸乙酯和巴豆酸乙酯的Antoine方程参数.用Wilson活度系数方程对实验数据进行了关联,取得了较好的结果. 相似文献
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The solubilities of ethyl palmitate, ethyl oleate, ethyl eicosapentaenoate (EPA) and ethyl docosahexaenoate (DHA) in supercritical
carbon dioxide were determined by a continuous flow method. The solubilities of fatty acid ethyl esters increased with pressure
and decreased as the temperature was increased. An empirical equation, similar to Chrastil's equation, was used to describe
the relationship between solute solubility and the density of carbon dioxide. The empirical equation was further used to qualitatively
estimate the separation efficiency of isolating EPA and DHA ethyl esters from fatty acid esters. The operating conditions
yielding high solubility gave fast extraction rate but resulted in low separation efficiency. Experiments were conducted to
separate ethyl EPA and ethyl DHA from a model mixture containing four fatty acid ethyl esters and from esterified squid visceral
oil. The experimental data compared closely with the calculated values. 相似文献
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纳米Cu-Zr-O催化剂催化乙醇脱氢合成乙酸乙酯 总被引:3,自引:0,他引:3
以纳米ZrO2为载体,采用浸渍法制备负载型CuO/ZrO2催化剂;以凝胶Zr(OH)4粉末为前驱物,制备掺杂型CuO-ZrO2催化剂;采用共沉淀法制备共沉淀型催化剂CuO·ZrO2。通过XRD、N2吸附、TEM和SEM对催化剂进行表征。以乙醇氧化脱氢合成乙酸乙酯为探针反应,考察Cu-Zr-O催化剂的催化性能。结果表明,3种催化剂均为纳米级颗粒,并对乙醇脱氢合成乙酸乙酯反应均有催化活性。共沉淀型CuO·ZrO2催化活性较好,在反应温度473 K,乙醇转化率为49%,乙酸乙酯选择性达88%。 相似文献
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更昔洛韦残留溶剂分析方法验证 总被引:1,自引:0,他引:1
更昔洛韦在生产过程中大量使用甲醇、乙醇、乙酸乙酯、N,N-二甲基甲酰胺,四者均属ICH限制使用的有机溶剂,其中甲醇、N,N-二甲基甲酰胺为二类溶剂,乙醇、乙酸乙酯为三类溶剂,为保证药品质量,对这两类溶剂均需加以控制。药品残留溶剂测定大多采用毛细管分析法,此法灵敏度高,对色谱系统影响小。参照《中国药典》2010年版二部附录"残留溶剂测定法",建立了甲醇、乙醇、乙酸乙酯和N,N-二甲基甲酰胺残留量测定方法。经各项方法学研究,确认方法简单、灵敏,准确度高,重现性好,适用于产品质量控制。 相似文献