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以甲醇与巯基乙酸为起始原料合成了3-氧代四氢噻吩-4-羧酸甲酯(Ⅲ),产物结构通过~1H NMR、~(13)C NMR、HRMS等表征。考察了无机碱(NaHCO_3、Na_2CO_3、K_2CO_3、NaOH、KOH)与有机碱(乙胺、三乙胺、吡啶、甲醇钠、甲醇钾)和不同溶剂以及温度对合成3-氧代四氢噻吩-4-羧酸甲酯收率的影响。结果表明,有机碱效果优于无机碱;甲苯为较优溶剂;高温反应有利于Ⅲ的合成。合成化合物Ⅲ的较优工艺为:甲苯作溶剂,吡啶为碱催化剂,在80℃下反应2h,收率可达78%。 相似文献
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本文报道了以(E)-1-(2-对甲苯磺酰胺基)-3-芳基丙-2-烯-1-酮(1)为底物与N-硫代丁二酰亚胺(2)通过亲电环化反应合成2-芳基-3-硫代-2,3-二氢喹啉-4(1H)-酮类化合物。以三氟化硼乙醚为催化剂(20 mol %),1,2-二氯乙烷为溶剂,反应温度为60 oC,可以60-92%的收率得到一系列2-芳基-3-硫代-4(1H)-喹啉酮衍生物,化合物3a-k均未见文献报道,其结构均经过1H NMR, 13C NMR以及高分辨质谱进行确定。 相似文献
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蒽酮1和氯甲基吡啶盐酸盐2在甲苯中回流反应生成10,10-二吡啶甲基-9(10H)蒽酮(3),收率63%~68%;3用硼氢化钠还原生成10,10-二吡啶甲基-9,l0-二氢蒽-9-醇(4),收率87%~90%;蒽醇4在酸催化下发生歧化反应,得到还原产物10,10-二吡啶甲基-9,10-二氢蒽(5)和氧化产物蒽酮3.该歧化反应受催化剂、溶剂和反应温度等影响.当蒽醇4用三氟化硼为催化剂、甲苯为溶剂、回流反应,5的收率达到74%.所合成的新化合物都经1H NMR,13C NMR,MS和元素分析表征确认. 相似文献
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1,4-二氢-4-芳基-3,5-吡啶二羧酸酯的合成及表征 总被引:1,自引:0,他引:1
基于二氢吡啶化合物的构效关系, 设计了一系列1,4-二氢-4-芳基-3,5-吡啶二羧酸酯新化合物. 含有易于水解基团的1,4-二氢-4-芳基-3,5-吡啶二羧酸酯类化合物在碱性条件下水解合成了重要中间体1,4-二氢-4-芳基-3,5-吡啶二羧酸单酯, 收率93%~99.8%. 该二羧酸单酯与α-溴代芳基乙酮在相转移剂催化下反应合成目标化合物, 收率74%~99%. 中间体和目标化合物经1H NMR, 13C NMR, IR, MS和元素分析等确证. 相似文献
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报道了一种斑蝥素的常压合成方法。以3-氧代-4-甲酸甲酯四氢噻吩为起始原料,经氰基化和腈醇脱水反应制得3-氰基-4-甲酸甲酯-2,5-二氢噻吩(1); 1水解制得2,5-二氢噻吩-3,4-二羧酸(2); 2在二氯亚砜作用下脱水制得关键中间体2,5-二氢噻吩-3,4-二羧酸酐(3); 3依次经D-A反应和Raney Ni催化加氢的脱硫反应合成了斑蝥素(5),总收率38%,其结构经1H NMR, 13C NMR和MS(ESI)确证。研究了离子液体、反应时间和反应温度对D-A反应的影响。确定D-A反应的较优条件为:[BMIM]·BF4为离子液体,于35 ℃反应20 h,斑蝥素前体产率为86%。 相似文献
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Kebing Wang Jie Yao Yue Wang Gongying Wang 《天然气化学杂志》2007,16(3):286-292
The coupling reaction of formaldehyde(FA)and methyl formate(MF)to form methyl glycolate(MG)and methyl methoxy acetate(MMAc),catalyzed by p-toluenesulfonic acid(p-TsOH)as well as assisted by different kinds of solvents or Ni-containing compounds,had been investigated.The results showed that when the reaction was carried out at 140℃,with a molar ratio of FA to MF of 0.65:1, molar fraction of p-TsOH to total feedstock of 11.0%,and reaction time of 3 h,the yield of MG and MMAc was 31.1% and 17.1%,respectively,p-TsOH catalyzed the coupling reaction by means of the synergistic catalysis of protonic acidity and soft basicity.Adding extra solvents to the reaction system was unfavorable for the reaction.The composite catalytic system consisting of p-TsOH and NiX_2(X=Cl,Br,I)exhibited a high catalytic performance for the coupling reaction,and NiX_2 acted as a promoter in the reaction,whose promotion for the catalysis increased in the following order:NiCl_2相似文献
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We report ignition delay time measurements for methyl propanoate (MP) and methyl acrylate (MA), carried out in a high-pressure shock tube. Experiments were performed behind reflected shock waves across a temperature range of 989-1 367 K, for fuel-air mixtures at equivalence ratios of ϕ = 0.5, 1.0, and 2.0, and nominal pressures of 1 and 4 MPa. Ignition delay times were found to decrease with increasing temperature, equivalence ratio, and pressure, and are well described with correlations involving Arrhenius temperature dependence and power-law dependence on equivalence ratio and pressure. Ignition delay times are compared with model predictions from literature kinetic models, with the models of Zhang et al (Energy & Fuels 2014; 28(11): 7194-7202) and Bennadji et al (International Journal of Chemical Kinetics 2011; 43(4): 204-218.) in good agreement with measured ignition delay times for MP and MA, respectively. Kinetic sensitivity analysis shows that the reactions most important for modeling ignition fall into two categories: initiation reactions (ie, decomposition and H-atom abstraction) and C0-C1 chemistry controlling the pool of small radicals. The unsaturated MA was observed to have lower reactivity than MP, due to its greater bond strengths for C─C and C─H bonds, resulting in slower rates for initiation reactions. 相似文献
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Nickel-basedcatalystsarewidelyusedinthechemicaliridustry,suchasinhydrogenation,steamreforming,andmethanationreactions1.Thecatalyticperformancesofnickelcatalystsaresensitivetopreparationmethods,supportsandpromoters=.ThecatalyticconversionofmethylformatetomethylacryIateisaveryinterestingprocess,inwhich,viamethyIformate,thetranspoFtandhand1ingCO/CH,OHatlocationswherethelatteraredifficulttoobtainortohandlecanbesimplified'.Nickel-basedcatalystswerepreparedbywetimpregnationusingoneofNi(NO,),,Ni… 相似文献
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以糠酸、甲醇、氢气为原料,采用连续流动固定床微反应器,Pd-Ni/γ-Al2O3为催化剂,使糠酸一步加氢甲酯化生成α-四氢糠酸甲酯.研究了反应的温度,压力,气、液体流速,进料流量等因素对催化反应的影响.结果表明:在1.5MPa,250℃,氢气空速3300 h-1,液体空速3.0 h-1(氢油比为50)时,糠酸转化率为96.6%,四氢糠酸甲酯的选择性97.2.0%,产率94.0%.催化剂稳定性较好,连续运转280小时后未见活性下降.该反应体系活性高,选择性好,反应压力低,催化剂性能稳定,操作简单,产物易分离. 相似文献
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Yu. N. Polivin R. A. Karakhanov V. A. Vinokurov M. A. Silin A. A. Bratkov 《Russian Chemical Bulletin》1992,41(2):324-328
We have investigated the reactions of aromatic carboxylic acids (p-XC6H4COOH, in which X=F, Cl, Br, I, NO2, CH3, H, OCH3) with methyl thiocyanate in trifluoroacetic acid. It was shown that the starting acids are converted to S-methyl benzothioates [p-XC6H4COSCH3 (40–70%)] and the nitrile of the acid [p-XC6H4CN (20–50%)]. In addition to starting acid, in the reaction mixtures products of the reaction of CF3COOH with methyl thiocyanate were identified.Institute of Oil and Gas Problems, Russian Academy of Sciences, I. M. Gubkin State Academy of Oil and Gas, 117917 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 412–416, February, 1992. 相似文献
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以α-甲基葡萄糖苷和硬脂酸甲酯为原料,在碱性催化剂K2CO3和相转移催化剂四丁基氯化铵(TBAC)共同作用下,无溶剂法合成了甲基葡萄糖苷硬脂酸酯(SS),再与环氧丙烷反应,合成了甲基葡萄糖苷硬脂酸酯聚氧丙烯醚(SSP),并对产品进行了IR表征.探讨了相转移催化酯交换反应机理.研究了原料配比、催化剂种类及用量、反应温度、反应时间等因素对SS收率的影响,得到了合成SS的适宜工艺条件:n(甲基葡萄糖苷)∶ n(硬脂酸甲酯)=0.71∶ 1,w(K2CO3)∶ w(硬脂酸酸甲酯)=0.04∶ 1,w(TBAC)∶ w(硬脂酸甲酯)=0.05∶ 1,反应温度145℃,时间4.5h,压力6kPa.上述条件下,SS收率可达92%,产品质量较好. 相似文献
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Two-step preparation for catalyst-free biodiesel fuel production 总被引:10,自引:0,他引:10
Biodiesel fuel was prepared by a two-step reaction: hydrolysis and methyl esterification. Hydrolysis was carried out at a
subcritical state of water to obtain fatty acids from triglycerides of rapeseed oil, while the methyl esterification of the
hydrolyzed products of triglycerides was treated near the supercritical methanol condition to achieve fatty acid methyl esters.
Consequently, the two-step preparation was found to convert rapessed oil to fatty acid methyl esters in considerably shorter
reaction time and milder reaction condition than the direct supercritical methanol treatment. The optimum reaction condition
in this two-step preparation was 270°C and 20 min for hydrolysis and methyl esterification, respectively. Variables affecting
the yields in hydrolysis and methyl esterification are discussed. 相似文献
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The hydroboration reaction of methyl cyanide has been investigated by the MNDO method. It has been shown that the reaction requires an activation energy of 25.3 kcal/mol and involves a four-center-like transition state in the rate-determining step. This reaction has been compared with the corresponding reaction of hydrogen cyanide, and the effect of methyl substitution on the reaction has been discussed. The charge-transfer effects accompanying the reaction have also been studied. 相似文献