共查询到19条相似文献,搜索用时 297 毫秒
1.
本文研究了在酸性离子液体的催化作用下α-甲基苯乙烯二聚合成1,1,3-三甲基-3-苯基茚满。实验结果表明,在无溶剂的条件下室温离子液体(CH3CH2)3NHCl-AlCl3对该反应具有很高的催化活性和目标产物的选择性,反应进行到5min即可达到100%的α-甲基苯乙烯转化率和97%的环状二聚物1,1,3-三甲基-3-苯基茚满的选择性。 相似文献
2.
以α-甲基苯乙烯为原料,SnCl4为催化剂高效合成了1,1,1-三甲基-3-苯基茚满,考察了影响1,1,1-三甲基-3-苯基茚满收率的各种因素,确定最佳反应条件为:催化剂用量为α-甲基苯乙烯质量的1%,反应温度140℃,反应3h,1,1,1-三甲基-3-苯基茚满收率可达92%以上。结果表明,SnCl4具有催化活性好,环境污染小的特点,是合成1,1,1-三甲基-3-苯基茚满的良好催化剂。 相似文献
3.
4.
5.
以1,3,3-三甲基-1-苯基茚满为原料,与硝-硫混酸进行硝化反应合成5(6)-硝基-1-(4-硝基苯基)-1,3,3-三甲基茚满(DNPI),用红外光谱(FTIR)和核磁共振氢谱(^(1)H-NMR)对其结构进行了表征,对硝化反应溶剂、反应时间、反应温度和物料配比进行考察。结果表明:n(1,3,3-三甲基-1-苯基茚满)∶n(硝酸)∶n(硫酸)=1.00∶2.15∶6.00,氯仿为溶剂,在25℃下反应时间3 h,DNPI的粗收率为98.6%。对优化后的工艺进行反应热安全风险测试和评估,得到硝化反应工艺的危险度等级为1级。 相似文献
6.
7.
以1,1,2,3,3-五甲基茚满与环氧丙烷为原料,二氯甲烷为溶剂,无水氯化铝催化合成2-(1,1,2,3,3-五甲基茚满)异丙醇(俗称茚满醇)。考察了原料摩尔比、无水氯化铝用量、反应温度对茚满醇选择性的影响。采用超声辅助溶解-结晶的方式对产品进行了纯化。结果表明,在-10~-15℃时,原料摩尔比n(五甲基茚满)∶n(环氧丙烷)∶n(无水氯化铝)=1∶1.2∶1.2的条件下反应2 h,五甲基茚满转化率55.8%,茚满醇选择性99%。经结晶纯化后茚满醇纯度达99%,避免了减压蒸馏产生的焦杂味。通过FTIR、GC-MS、HRESIMS、元素分析、1HNMR和13CNMR对茚满醇结构进行了表征。 相似文献
8.
研究了离子液体作为助催化剂催化氧化2,3,6-三甲基苯酚合成2,3,5-三甲基苯醌的反应。催化剂CuCl2和MnCl2的用量分别为2,3,6-三甲基苯酚物质的量的10%,助催化剂离子液体1-丁基-3-甲基咪唑四氟硼酸盐用量为2,3,6-三甲基苯酚物质的量的20%,空气中的氧气为氧化剂, 80 ℃反应4 h,转化率100%,选择性92.60%。在后处理过程中,离子液体易于分离和回收利用,为工业合成2,3,5-三甲基苯醌提供了一种较好的选择。 相似文献
9.
10.
11.
The catalytic systems composed of ionic liquids containing BF4− anion and HBF4 showed high catalytic activity to produce 4-methyl-2,4-diphenyl-1-pentene (MDP-1) or 1,1,3-trimethyl-3-phenylindan (TPI)
under different temperature conditions. Up to 90.8% selectivity to MDP-1 with a 98.7% conversion of α-methylstyrene was obtained
at 60 °C in the presence of [HexMIm]BF4–HBF4, while exclusive TPI was yielded when the reaction temperature increased to 120 °C. Further studies showed that another ionic
liquid, [BMIm]Cl · 2AlCl3, could act as an excellent catalyst and solvent for the dimerization of α-methylstyrene to produce TPI. The dimerization
of α-methylstyrene catalyzed by [HexMIm]BF4–HBF4 and [BMIm]Cl · 2AlCl3 performed the same reaction mechanism and the proton was the active species. 相似文献
12.
《Catalysis communications》2007,8(7):1153-1155
At 60 °C, the Wells–Dawson tungsten heteropolyacid H6P2W18O6 2 catalyzes the selective formation of 1,1,3-trimethyl-3-phenylindan from α-methylstyrene. 相似文献
13.
《Catalysis communications》2011,15(1):89-91
In the presence of catalytic amounts of a Keggin (H3PW12O40), Wells–Dawson (H6P2W18O62) or Preyssler (H14NaP5W30O110) heteropolyacid, α-methylstyrene (1) leads to dimers. The efficiency and the selectivity toward 2,4-diphenyl-4-methyl-1-pentene (2), 2,4-diphenyl-4-methyl-2-pentene (3) and 1,1,3-trimethyl-3-phenylindan (4) depend on the reaction temperature and the nature of both the catalyst and the solvent. Thus, 2, 3 and 4 can be produced in 45%, 50% and 97% yields, respectively. 相似文献
14.
为了避免挥发性有机溶剂造成环境污染,研究了无溶剂条件下的Knoevenagel缩合反应。以功能性离子液体乳酸乙醇胺盐作催化剂,在无溶剂条件下实现了苯甲醛、甲基苯甲醛、甲氧基苯甲醛、氯代苯甲醛和呋喃醛等芳香醛与氰基乙酸乙酯或丙二腈的Knoevenagel缩合反应。反应在室温条件下,数分钟至1 h内完成,收率81%~98%。反应选择性好,只生成E-烯烃,产物分离过程简便,通过简单的乙醇水溶液洗涤和重结晶即可分离出产物。初步讨论了功能性离子液体乳酸乙醇胺盐催化的Knoevenagel缩合反应机理。 相似文献
15.
Friedel-Crafts alkylation of benzene with benzyl chloride was studied by using organochloroaluminate ionic liquids as Lewis
acid catalyst. The reaction was performed in the temperature range of 40 to 70 oC at benzene/ benzyl chloride=17, where selectivity
to diphenylmethane was high. The optimum AlCl3/BMIC ratio of the ionic liquid for the benzylation reaction was 2. Superior
performance was obtained with butyl group constituting the cationic species of the ionic liquid. Stirring speed had a major
impact on catalytic activity of the BMIC-AlCl3 ionic liquid; benzyl chloride conversion decreased substantially from 98 to
68% as stirring speed was reduced from 900 to 500 rpm, and eventually no reaction took place at 200 rpm. BMIC-AlCl3 ionic
liquid was more active than Fe-MCM-41 at the expense of a small drop in selectivity but still higher than 96% selectivity
was obtained. The ionic liquid could be easily recovered after phase separation. The performance of BMIC-AlCl3 ionic liquid was maintained after the second run with 97.4% conversion and 95.6% selectivity, but a sudden drop in activity
was observed after the third run with only 26.8% conversion. 相似文献
16.
针对硝基苯催化加氢合成对氨基苯酚(PAP)的过程,提出了Pt/SiO2和新型季铵型Brφnsted酸性离子液体N,N,N-三甲基-N-磺丁基硫酸氢铵([HSO3-b-N(CH3)3]HSO4)构成的双功能催化体系。考察了离子液体浓度、Pt/SiO2用量及操作条件对对氨基苯酚收率和选择性的影响。并与硫酸体系进行了对比。在85℃、4 h、0.4 MPa条件下,硝基苯转化率96.6%,对氨基苯酚的选择性为81.4%,优于Pt/SiO2和硫酸溶液体系。可能的原因是,离子液体增加了硝基苯溶解度,并且抑制了中间产物苯基羟胺的深度加氢。反应后用减压过滤可分离出Pt/SiO2催化剂;滤液经由萃取、减压蒸馏和结晶析出PAP。结果证明,该双功能催化体系重复使用3次,PAP收率没有明显的下降。 相似文献
17.
2-Methyl-4-methoxyaniline (MMA) was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The effects of ionic liquid type, dosage of ionic liquid and 3% Pt/C, reaction temperature and reaction pressure on o-nitrotoluene conversion and MMA selectivity were investigated. The results indicated that the imidazolium-based acidic ionic liquid which contains SO3H-functionalized cation showed higher selectivity to MMA than other acidic ionic liquids used in this work. Using 1-(propyl-3-sulfonate)-3-methylimidazolium hydrosulfate ([HSO3-pmim][HSO4]) as the acid catalyst, the selectivity to MMA was as high as 67.6% at 97.8% of o-nitrotoluene conversion. As 3% Pt/C increased from 0.01 g to 0.025 g, the selectivity to MMA decreased from 73.4% to 62.5%, because of the hydrogenation of intermediate o-methyl-phenylhydroxylamine to o-toluidine becoming more dominant. An increase in hydrogen pressure also had obviously dramatic effect in lowering the MMA selectivity. After easy separation from the products, the catalyst system could be reused at least 3 times. 相似文献
18.
《Gas Separation & Purification》1994,8(3):149-160
The gas separation properties of new aromatic poly-1,2,4-triazole and poly-1,3,4-oxadiazole membranes have been systematically investigated. Various functional groups were incorporated as pendent groups onto the polymer backbone of poly-1,2,4-triazoles. A wide permeability/selectivity spectrum was covered with the choice of functional groups incorporated into the polymer backbone of poly-1,3,4-oxadiazoles. High permeabilities were found for poly-1,3,4-oxadiazoles with a 1,1,3-trimethyl-3-phenylindane (PIDA-POD) and a 4,4′(2,2′-diphenyl)hexafluor propane (HF-POD) unit in the polymer backbone, while incorporation of a 4,4′-diphenyl ether unit (DPE-POD) results in a polymer with a low permeability but an extremely high selectivity. While the permeabilities vary over four orders of magnitude, the solubility remains almost constant and, therefore, the increase in permeability is mainly due to an increase in diffusivity. The permeability is discussed in terms of the polymer free volume. 相似文献
19.
Summary Three new symmetrical alkylaromatic sturctures p-bis(3-chloro-1,1,3-trimethylbutyl)benzene (I), p-bis(1,1,3-trimethyl-3-butenyl)benzene (II), and 1,1, 3,3,5,5,7,7-octamethyl-s-hydrindacene (III) have been synthesized. These new model compounds were needed to study the mechanism of intramolecular cycloalkylation (indane-skeleton formation) during the preparation of telechelic polyisobutylenes by the inifer technique. The 13C NMR spectrum of polyisobutylene obtained by the p-dicumyl chloride/BCl3 inifer system has been analyzed and the resonances identified. 相似文献