共查询到19条相似文献,搜索用时 62 毫秒
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以[1-甲基-2-(4′-丁酸乙酯基)-5-氨基]-1H-苯并咪唑为原料,与氯乙醇经-N-单羟乙基化反应制得[1-甲基-2-(4′-丁酸乙酯基)-5-(2′-羟基乙基)氨基]-1H-苯并咪唑(A); A与氯化亚砜经氯化反应制得[1-甲基-2-(4′-丁酸乙酯基)-5-(2′-氯乙基)氨基]-1H-苯并咪唑(B); B在浓盐酸中经水解成盐反应合成了盐酸苯达莫司汀杂质[1-甲基-2-(4′-丁酸基)-5-(2′-氯乙基)氨基]-1H-苯并咪唑盐酸盐,总收率24.5%,纯度98.12%,其结构经1H NMR, 13C NMR和HR-MS(ESI)确证。 相似文献
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以苯亚磺酸钠和氯乙酸乙酯为起始原料,首先合成苯砜乙酸乙酯(Ⅰ);再与由1,1,3,3-四甲氧基丙烷与二乙胺反应得到的N,N-双乙基胺-1,3-二丙烯醋酸盐反应,得5-二乙基氨基-2-苯磺酰基-2,4-戊二烯乙酸乙酯(Ⅱ)中间体;最后与正辛醇酯交换得到目标产物5-二乙基氨基-2-苯磺酰基-2,4-戊二烯乙酸辛酯(DPO)。考察了溶剂的种类对制备化合物Ⅰ和投料比、反应温度对制备化合物Ⅱ的影响,并且通过重结晶法纯化DPO产品,最终可使产品DPO收率达到69.58%、产品纯度大于99.50%,并通过LC-MS和1H NMR对产品及中间产品进行了结构分析与确证。 相似文献
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以苯甲醇、苯酚为起始原料,在活性A l2O3催化作用下,通过C laisen重排反应得到关键中间体2-苄基苯酚,再经过醚化、胺化、酸化反应得到一种新型结构的二苯美仑类化合物.反应过程经优化使中间体2-苄基苯酚产率较文献提高8%.合成的新化合物经IR,1H NMR及元素分析表征. 相似文献
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以(S)-2,6-二氨基-4,5,6,7-四氢苯并噻唑(3)为原料,经缩合、还原反应制得普拉克索(2); 2与盐酸成盐后制得盐酸普拉克索一水合物(1),其结构经1H NMR, 13C NMR, IR和MS(ESI)确证。研究了溶剂、反应温度、投料比γ[n(3) : n(正丙醛)]、析晶终止温度和精制降温速度对1收率的影响。结果表明:在最佳反应条件(无水甲醇为溶剂,γ=1.0 : 1.8,于-15~-20 ℃反应,析晶终止温度为-5~-10 ℃)下,最高收率可达61.5%。 相似文献
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María del Mar Graciani Amalia Rodríguez María Mu?oz María Luisa Moyá 《Reaction Kinetics and Catalysis Letters》2003,78(1):113-119
The 1-chloro-2,4-dinitrobenzene + OH- reaction was studied in tetradecyltrimethylammonium bromide aqueous micellar solutions. Influence of changes in [surfactant]
as well as in [NaOH] on the observed rate constant were rationalized by using pseudophase kinetic models. At high hydroxide
ions concentration an additional pathway across the micellar boundary had to be considered.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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In 1-chloro-2,4-dinitrobenzene (CDNB) manufacture, the washing process discharges a large amount of CDNB-rich acidic effluent: a very aggressive and toxic wastewater. The concentration of CDNB reaches up to 332.2mg/L. CDNB has been known as an intracellular glutathione-depleting agent and shown to have an adverse effect on erythrocyte membrane integrity and caused aemolysis of human red blood cell. 1 Its removal from wastewater is necessary for health and environmental reason.Two main techniques have been used for the decontamination of CDNB-containing wastewater:activate-carbon adsorption and biodegradation. Biodegradation method works well in summer.However in winter, the activity of animalcules decreases dramatically with the dropping of temperature. Adsorption of CDNB on fresh active-carbon is quick and efficient. However once saturated, active-carbon loses adsorption capacity sharply. The revival of active-carbon by flash steam blowing or sweeping proves to be sluggish and inefficient. Therefore frequent change and replenish of active-carbon is necessary which results in significant operating cost.In this study, we disclose an easy-operating and sustainable method for the treatment of CDNB-contaminated wastewater, which not only removes the toxic CDNB from wastewater and readily revives the active-carbon, but also produces another useful chemical 2,4-dinitrophenol(DNP). Our method is based upon the physical adsorption of CDNB on active-carbon and the chemical conversion of CDNB to SDNP and then to DNP. As a well known nucleophilic substitution example, chlorobenzene with one/two/three NO2, a very strong electron-withdrawing group, at its ortho- and/or para- positions can be readily hydrolysed to give the corresponding phenols under basic condition (Scheme 1).First, the CDNB-contaminated wastewater was treated with active-carbon at room temperature.CDNB was thus adsorbed on to active-carbon physically. The CDNB-loaded active-carbon was filtered off. The acidic filtrate was neutralised by aqueous Ca(OH)2 to give recyclable water or environmental friendly wastewater.Second, the loaded active-carbon was refluxed with aqueous alkaline which converts CDNB into water-soluble sodium 2,4-dinitrophenolate (SDNP). CDNB was therefore desorbed from active-carbon. Filtration of the suspension while hot followed by washing with hot water led to the revival of active-carbon. The revived active-carbon showed similar adsorption capacity to the fresh counterpart and can be recycled to treat the wastewater again and again. Third, acidification of the filtrate containing SDNP to pH = 4 led to nearly quantitative precipitation of DNP as crystals, which can be collected by filtration as another useful dye intermediate. 相似文献
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《Analytical letters》2012,45(6):995-1003
Abstract The use of 1-chloro-2, 4-dinitrobenzene is described for spectrophotometric estimation of ascorbic acid. The procedure is based on the interaction of ascorbic acid with 1-chloro-2, 4-dinitrobenzene in alkaline medium. The product absorbs maximally at 380 nm and has the molar absorptivity 0.14 × 1041 mole?1cm?1. Beer's law is obeyed in the concentration range 0.12–0.6 mg/10ml of ascorbic acid. 相似文献
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Deep eutectic solvents seem to be environmentally friendly solvents, particularly because they are prepared easily and have very low-vapor pressures under ambient conditions. They are suitable candidates as green solvents for reaction media with special properties. To present this behavior, substitution reactions of some para- and meta-substituted anilines with 1-fluoro-2,4-dinitrobenzene have been spectrophotometrically investigated in varying mole fractions of ethaline as a deep eutectic solvent in dimethyl sulfoxide (DMSO). The measured rate coefficients of the reaction demonstrated a noticeable variation with the increasing mole fraction of ethaline in ethaline-DMSO mixtures. The linear free energy relationship (LFER) of second-order rate coefficients based on Hammett's substituent constants demonstrates a reasonably linear straight line with a negative slope in different mole fractions of ethaline-DMSO mixtures. Another LFER investigation based on the polarity parameters of the media showed a good agreement with hydrogen bond donor and acceptor abilities of the solvent. Non-LFER assay according to the preferential solvation model confirmed differences between the microsphere solvation of the solute molecules and the bulk composition of the solvents. 相似文献
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《Analytical letters》2012,45(2):202-219
Diastereomers of three β-blockers (orciprenaline, betaxolol, and propranolol) were synthesized using three new chiral derivatizing reagents that were prepared by substituting one fluorine atom in 1,5-difluoro-2,4-dinitrobenzene with two chirally pure amines and one L-amino acid. The reagents were characterized using ultraviolet-visible spectroscopy, infrared spectroscopy, elemental analysis, and proton nuclear magnetic resonance. Diastereomers were synthesized under microwave irradiation at 50 s at 80% of 800 W and also by stirring for 50 min at 45°C. The diastereomers were separated by reversed-phase high-performance liquid chromatography on a C18 column with detection at 340 nm using acetonitrile and aqueous trifluoroacetic acid as the mobile phase components. The conditions of derivatization and chromatographic separation were optimized. The method was validated for accuracy, precision, limit of detection, and limit of quantification. 相似文献
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A simple, accurate and selective method is described for the determination of morphine in illicit powders, based on monitoring the initial rate of fluoride ion liberation from the reaction of morphine with 1-fluoro-2,4-dinitrobenzene at pH 9 and 35 °C, using a solid-state fluoride ion-selective electrode. Under optimized reaction conditions, as little as 15 g/ml of morphine is determined with an average recovery of 99.5% and a mean relative standard deviation of 1.2%. Determination of morphine in real illicit powders containing 6–18% morphine gives results comparing favorably with those obtained from isocratic reverse-phase high-performance liquid chromatography. No interferences are caused by many structurally related and associated compounds such as codeine, acetylcodeine, ethylmorphine, acetylmorphine and diacetylmorphine (heroin). 相似文献
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通过对艾拉莫德重要中间体的的合成改进和优化,提高艾拉莫德的收率和纯度.以4-氯-3-硝基苯甲醚为原料经亲核取代反应、硝基还原、甲磺酰化、Houben-Hoesch反应、甲酰化、甲氧基脱甲基化和环合,共7步反应合成艾拉莫德.总收率42.49%,纯度100%. 相似文献