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3,4-二氟苯腈是制备除草剂氰氟草酯的重要中间体.介绍了3,4-二氟苯腈的7种合成方法,即3,4-二氯苯腈直接氟化路线、3,4-二氟甲苯路线、3,4-二氟苯甲酸脱水路线、1-溴-3,4-二氟苯路线、4-氯苯腈路线、3,4-二氟硝基苯重氮化路线和3,4-二硝基甲苯路线.对各种方法在农药生产上的应用和市场前景做了简单的分析,并对3,4-二氯苯腈催化直接氟化法做了重点评述,是一条易于实现工业化的合适路线. 相似文献
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为优化2,6-二氟苯甲酸(DFBA)的合成工艺,以2,6-二氯苯腈(DCBN)和氟化钾为原料,N,N-二甲基酰胺(DMF)为溶剂,在聚醚类催化剂A的催化下氟代合成中间体2,6-二氟苯腈,然后中间体在碱性条件下水解制得(DFBA).试验结果表明,合成DFBN的最佳条件为:DCBN在DMF中的质量浓度为0.38g/mL,KF的量为DCBN的量的2.3~2.4倍,反应时间10 h,最高收率93.5%;合成DFBA时,以质量分数为20%的NaOH为介质,反应时间9 h,收率≥92%.收率93.5%,纯度99.7%.该工艺收率高、三废排放少,可节省成本,有望工业推广. 相似文献
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3,4-二氟苯腈是一种重要的中间体,目前合成方法有采用3,4-二氯苯腈为原料,通相转移催化制备,由此建立了反应过程中同时测定3,4-二氟苯腈和3,4-二氯苯腈的高效液相色谱定量分析方法。以C18色谱柱为分离柱,70%甲醇水溶液为流动相;紫外检测波长设定为210 nm,可以实现反应液中这两种物质的同时检测。3,4-二氟苯腈和3,4-二氯苯腈的最低检出浓度分别为0.04和0.03μg/m L,线性范围分别为0.1~500和0.1~100μg/m L,方法的回收率为92%~106%,相对标准偏差(RSD)为1.0%~2.5%。此外,进一步考察C18 SPE小柱富集微量3,4-二氯苯腈的方法,可以实现3,4-二氟苯腈粗品中3,4-二氯苯腈的含量分析,自制的3,4-二氟苯腈样品中,3,4-二氯苯腈的含量为0.2%,加标回收率为97%。 相似文献
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简要综述了2,6-二氟苯腈的合成方法及其在农药合成中的应用,探讨了各种合成路线的优缺点。由2,6-二氟苯腈衍生的2,6-二氟苯甲酰胺等化合物是合成苯甲酰脲类杀虫杀螨剂和除草剂的重要原料。这是一种具有广阔市场发展前景精细化工中间体。 相似文献
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氟虫腈是全球最重要的杀虫剂之一,国内专利已经到期,该农药被国家相关部门推荐为高毒有机磷农药的主要替代品种,具有良好的市场前景。重点介绍了氟虫腈及其主要中间体4-三氟甲基苯胺、2.6-二氟-4-三氟甲基苯胺的合成技术进展。 相似文献
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2-羟基-2-甲基-1-苯基丙酮的合成 总被引:3,自引:0,他引:3
以苯甲醛、镁、2 -溴丙烷、溴等为主要原料 ,经四步反应合成了光敏引发剂 2 -羟基 - 2 -甲基 - 1 -苯基丙酮。在 0°C时 ,将 1 6.5g苯甲醛滴加到由 4g Mg和 2 0 .6g2 -溴丙烷制得的 Grignard试剂中 ,在室温下搅拌 0 .5h,得到 2 0 .5g异丙基苯甲醇。将 2 5g K2 Cr2 O7、1 1 0 m L水和 2 0 m L浓H2 SO4 的混合液加入由 90 m L氯仿、5m L新洁而灭和 35g异丙基苯甲醇组成的混合液中 ,加完后 ,在室温下继续搅拌 2 h,得到 2 9.5g异丙基苯甲酮。在 65~ 75°C,将 32 .5g Br2 和 30 m L四氯化碳滴加到 60 m L CCl4 、1 5m L醋酸和 2 8.5g异丙基苯甲酮中 ,在温度不超过 70°C时搅拌 3h,得到α-溴代异丙基苯甲酮。1 0 gα-溴代异丙基苯甲酮、32 m L质量分数为 1 0 %的 Na OH溶液及 5m L新洁而灭 ,加热回流 3h,得到 6.8g 2 -羟基 - 2 -甲基 - 1 -苯基丙酮。 相似文献
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The synthesis of N-vinyl caprolactam (NVCL), with acetylene as alkylene agent, was studied in a stirred reactor system. With potassium hydroxide (KOH) being used as catalyst and 18-crown-6 ether as cocatalyst, NVCL was synthesized by the reaction of acetylene with caprolactam (CL). Crude products were purified by vacuum distillation. The addition of 18-crown-6 ether accelerates the reaction rate of the nucleophilic addition much greatly. The initial explanation suggests that the hole radius of 18-crown-6 ether is close to the one of K+. A complex is formed between 18-crown-6 ether and K+ ion on the formed intermediate of potassium caprolactam, so the addition reaction between acetylene and caprolactam was accelerated greatly. In the stirred tank reactor (500 mL four flask bottle), the CL conversion is 30.5% and the product selectivity is up to 73.4%. The experimental data indicate that the product mixture is a non-ideal liquid mixture. A single process of distillation is difficult to obtain a high purity NVCL product. The combination of extraction and distillation is an ideal separation process for producing high purity NVCL. 相似文献
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Dae-Jin Kim Jun-Woo Kim Eui Jung Kim Kee-Kahb Koo 《Korean Journal of Chemical Engineering》2011,28(4):1120-1125
One-dimensional (1-D) ZnTe nanowires were prepared by aerosol-assisted spray pyrolysis using a mixture of ZnO (1 mmol)/OA
(4 mL)/TOPO (0.8 g)/ODE (4 mL) as Zn precursor and Te/TOP (3 mL of 0.75M) as Te precursor. The shape, size, and crystal structure
of products were characterized by means of transmission electron microscope (TEM) and X-ray diffraction (XRD). The shape evolution
of ZnTe nanocrystals from nanodots to nanowires was achieved by controlling the reaction temperature. ZnTe nanodots with average
diameter of 8.3 nm were synthesized at 300 °C. “Earthworm-like” shaped ZnTe (linear ZnTe aggregates) consisting of primary
ZnTe nanodots of about 16 nm in diameter were obtained at 400 °C. In addition, 1-D ZnTe nanowires were prepared at reaction
temperature higher than 450 °C. Those experimental results suggest that ZnTe nanowires with zinc blende structure are formed
from ZnTe nanodots by the oriented attachment due to insufficient surface capping of surfactant molecules and by strong dipole-dipole
interaction of nanodots, followed by self-organization of linear aggregates at higher reaction temperatures. The linear ZnTe
aggregates consisting of primary ZnTe nanodots may be an intermediate stage in the formation process of nanowires from nanodots. 相似文献
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建立酶法反应中还原型/氧化型谷胱甘肽含量的液相分析方法。采用ZOABAX SB-C18进行分离,流动相为磷酸二氢钾辛烷磺酸钠溶液∶乙腈(920∶80,V/V),流速1.0 mL/min,检测波长210 nm,进样量20μL;采用外标法定量。还原型/氧化型谷胱甘肽在10~200μg/mL范围内线性关系良好,相关系数分别为0.9994(n=4)、0.9999(n=4),在S/N=3时最低检测限分别为0.037μg/mL、0.019μg/mL;在S/N=10时最低定量限分别为1.90μg/mL、1.12μg/mL;样品加标回收率分别为98.7%~100.6%、98.5%~101.4%;色谱系统稳定性RSD,GSH、GSSH分别为0.44%、1.16%。样品分析显示出本方法操作简便,快速,准确,灵敏度高,稳定性好,适合酶催化反应中还原型/氧化型谷胱甘肽的测定。 相似文献
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隔壁精馏塔由于其特殊的结构可在单塔内实现多组分高纯度分离的目的。本文针对Kaibel隔壁精馏塔(KDWC)分离四组分混合物的节能工艺进行了模拟优化和实验研究。以甲醇、乙醇、正丙醇和正丁醇(MEPB)为例,通过热力学分析建立了稳态模拟的“四塔模型”,并以塔内温度分布为依据对模型准确性进行了实验验证。提出了一种基于再沸器能耗的优化流程,以再沸器最小能耗为目标函数,对KDWC的液相分配比(RL)及整体结构进行了优化。分析了KDWC的节能原理并考察了中间组分含量对KDWC节能效果的影响。对比了KDWC与常规传统三塔序列的能耗并对二者的热力学效率进行了计算。结果表明:温度分布的模拟值与实验值趋于一致,且液相分配比(RL)是塔的重要操作参数;KDWC结构相比于传统三塔序列节能的重要原因是有效降低了中间组分(乙醇和正丙醇)的返混程度,且随着中间组分含量的增加KDWC节能效果越来越明显;当中间组分摩尔分数为80%时,KDWC可节能35.65%,可提高热力学效率26.11%。通过本文研究,为隔壁塔用于四组分精馏提供了基础实验数据并为其节能优化提供了理论指导。 相似文献
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Zakir Hossain Kenji Fukunaga Masatoshi Tanouchi Koretaro Takahashi 《European Journal of Lipid Science and Technology》2009,111(9):877-883
An animal experiment was conducted to assess the antitumor effects of chitosan‐coated liposomes on myeloma SP2. The animal experimental groups designed for myeloma SP2 tumor‐bearing BALB/c mice were provided with five different drinks: (I) control (double‐distilled water); (II) squid phospholipid liposomes alone 1.0 mg/mL; (III) chitosan alone 5.0 mg/mL; (IV) squid phospholipid liposomes 1.0 mg/mL with chitosan 5.0 mg/mL in the form of a simple mixture; and (V) squid phospholipid liposomes 1.0 mg/mL coated with chitosan 5.0 mg/mL. At 20 days after implantation of the myeloma SP2 cells into mice, oral administration of the experimental drinks was provided for 35 days. There was significant suppression of tumor growth when chitosan and squid phospholipids were administered simultaneously in a simple mixture or as chitosan‐coated liposomes. Matrix metalloproteinase (MMP)‐2 and MMP‐9 activity was significantly less in the serum of mice that consumed chitosan‐coated liposomes than in control mice. We found that decreased tumor burden was related to MMP secretion. Therefore, chitosan‐coated marine phospholipid liposomes might be useful as potential agents for the treatment of myeloma SP2. 相似文献