共查询到19条相似文献,搜索用时 515 毫秒
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详细地评述了新型绿色抗微生物剂2,4,4′-三氯-2′-羟基二苯醚的主要合成方法及其化学工业领域中的应用,分析了重氮化、酯交换、氧化及脱烷基化等工艺的特点,提出了2,4,4′-三氯-2′-羟基二苯醚的清洁生产工艺。 相似文献
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抗骨质疏松新药中间体7-羟基异黄酮合成技术进展 总被引:1,自引:0,他引:1
本文综述了国外近年开发的抗骨质疏松新药依普黄酮关键中间体7-羟基异黄酮的合成技术及其进展情况,并对其合成方法的优缺点进行了述评,指出以间苯二酚和苯乙酸为主要原料合成2,4-二羟基苯基苄酮,然后与原甲酸三乙酯环合的合成路线是较合适的工业化生产路线。 相似文献
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2-羟基苯基苯甲酮具有根好的杀菌活性,对白粉病有
特效。以5-溴-6,6‘-二甲基毛-羟基-2’,3’,4-三甲氧基苯基
苯甲酮为例,合成方法和具体操作简介如下: 相似文献
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α-羟基环己基苯基甲酮(光引发剂184)是一种高效光引发剂,因其引发效率高、稳定性好、耐黄变等优势,在电子、涂料、印刷等领域得到广泛的应用。本文根据起始原料不同对α-羟基环己基苯基甲酮的合成方法进行分类,并归纳了不同合成方法的特点。重点介绍了以环己基苯基甲酮为中间体的合成工艺以及其他合成α-羟基环己基苯基甲酮的工艺路线。目前,工业上最常用的Friedel-Crafts酰基化法合成光引发剂184的工艺路线,因为产生的三废多且有毒有害,不符合绿色化工的要求,而将逐渐被淘汰。以格氏反应法合成环己基苯基甲酮继而再合成α-羟基环己基苯基甲酮的工艺路线,因其收率高、污染少等优点而有望成为合成α-羟基环己基苯基甲酮的重要发展方向之一。最后,指出了α-羟基环己基苯基甲酮合成工艺研究的趋势。 相似文献
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《精细化工原料及中间体》2018,(12)
正本发明提供了一种合成巴多昔芬杂质的合成方法,以4-羟基苯乙醇为原料,苄氯保护酚羟基,二氯亚砜与苯乙醇反应生成苄氯,与中间体3-甲基-5-苄氧基-2-(4-苄氧基苯基)-1H-吲哚反应,钯碳催化加氢脱去苄基保护,获得巴多昔芬杂质。此方法无 相似文献
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4-苯基-2-丁酮俗名“止咳酮”。是许多合成药物和合成香料的重要中间体。溧阳制药厂在生产心血管新药“柳胺苄心定”时,原用戊二酮合成中间体“4-苯基-2-丁酮”,后改用乙酰乙酸乙酯合成,但原料均不易得,且价格较贵,增加了生产成本。 相似文献
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联苯苄唑中间体──4-苯基二苯酮合成方法的改进韩长日,宋小平(湖北师范学院化学系,黄石435002)4一苯基二苯酮是合成联苯节吐(bifonazole)的重要中间体。联苯节峻是一种不含卤素的咪哩类抗真菌药,具有很强的皮肤渗透性,在表皮深层药物浓度可达... 相似文献
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C_4齐聚烯烃中2,4,4-三甲基戊烯的精密分离 总被引:2,自引:0,他引:2
对从C4齐聚物分离2,4,4 三甲基戊烯的过程进行了精密分离研究,应用AspenPlus流程模拟系统为工作平台建立了数学模型,结合精确的定性和定量分析以及精馏热模试验,实现了最终目的产品2,4,4 三甲基戊烯纯度95%、收率98%的分离结果。 相似文献
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2,4,4′-三氯-2′-氨基二苯醚的合成 总被引:3,自引:0,他引:3
由对二氯苯通过硝化、缩合、还原等反应合成 2 ,4,4′ 三氯 2′ 氨基二苯醚 ,总收率 75 %。重点对缩合反应条件进行了探讨。最佳反应条件为 :物料物质的量比n( 2 ,5 二氯硝基苯 )∶n( 2 ,4 二氯苯酚 ) =1.0 0∶1.0 5 ;反应时间为 18h ,溶剂丁醇用量为硝基物和酚质量和的 1.5倍 相似文献
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Multi-Step Redox Systems. LXI. Synthesis of 1,4-Bis(2-methyl-indolizin-1-yl-methyl)-benzene and Related Model Compounds The synthesis of 1a , in which two 1-indolizine units are connected by a p-xylylene bridge is preformed from its 3,3′bis-acetyl derivative 1b via the precursors 8–11 . This route was first tested by the synthesis of benzyl indolizines 2b and 2a via the pyridyl-aminopropanol 3a. 2a can be oxidatively dimerized to the 3,3′-bis-indolizine 6 which forms a perfectly reversible two step redox system with KSEM = 4.7 × 105. 相似文献
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Mahavir Prashad 《Advanced Synthesis \u0026amp; Catalysis》2001,343(5):379-392
Various approaches to the preparation of enantiomerically pure (2R,2′R)‐(+)‐threo‐methylphenidate hydrochloride ( 1 ) are reviewed. These approaches include synthesis using enantiomerically pure precursors obtained by resolution, classical and enzyme‐based resolution approaches, enantioselective synthesis approaches, and approaches based on enantioselective synthesis of (2S,2′R)‐erythro‐methylphenidate followed by epimerization at the 2‐position. 1 Introduction 2 Methods for the Enhancement of Enantiomeric Purity of 1 3 Approaches Using Enantiomerically Pure Precursors Obtained by Resolution 4 Classical Resolution Approaches 4.1 Resolution of Amide and Acid Derivatives 4.2 Resolution of (±)‐threo‐Methylphenidate 5 Enzyme‐Based Resolution Approaches 6 Enantioselective Synthesis Approaches 7 Approaches Based on Enantioselective Synthesis of (2S,2′R)‐erythro‐Methylphenidate and Epimerization 8 Conclusions 相似文献
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对4-甲基-3-溴苯酚的合成进行了改进:简化了溴化反应的后处理步骤,解决了还原反应的后处理中Sn(OH)2胶体沉淀难以破坏的问题,改进了重氮盐水解反应的操作方法。按照改进的方法,以4-硝基甲苯为起始原料经4步反应合成目标化合物,总收率为53%。 相似文献
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Synthesis and properties of poly(imide-siloxane) hybrid polymers (PIS), having alternate diimide and disiloxane units, based on 1,3-bis(succinyl anhydride)1,1,3,3-tetraorganodisiloxane (I or II) have been described. Polymers have been synthesized by the precursor synthesis i.e., poly(amic acid), using siloxanes (I or II) and 4,4′-diaminodiphenylmethane (DDM) or 4,4′-diaminodiphenylsulphone (DDS) in N,N-dimethylacetamide (DMAc) followed by thermal imidization. FT-IR, thermal (TGA and TMA), solvent resistant and dielectric properties of the compounds have also been studied. The glass transition, thermal stability and char yields of these hybrid polymers increased appreciably. These materials also showed very good solvent resistant properties in protic and aprotic solvents. 相似文献
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The biocatalytic synthesis of xylooligosaccharides of daidzein was investigated using cultured cells of Catharanthus roseus and Aspergillus sp. β-xylosidase. The cultured cells of C. roseus converted daidzein into its 4'-O-β-glucoside, 7-O-β-glucoside, and 7-O-β-primeveroside, which was a new compound. The 7-O-β-primeveroside of daidzein was further xylosylated by Aspergillus sp. β-xylosidase to daidzein trisaccharide, i.e., 7-O-[6-O-(4-O-(β-d-xylopyranosyl))-β-d-xylopyranosyl]-β-d-glucopyranoside, which was a new compound. The 4'-O-β-glucoside, 7-O-β-glucoside, and 7-O-β-primeveroside of daidzein exerted DPPH free-radical scavenging and superoxide radical scavenging activity. On the other hand, 7-O-β-glucoside and 7-O-β-primeveroside of daidzein showed inhibitory effects on IgE antibody production. 相似文献