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相转移催化氧化法合成硝基苯甲酸 总被引:8,自引:0,他引:8
研究了季铵盐 A- 1催化高锰酸钾氧化邻、对硝基甲苯 ,合成邻、对硝基苯甲酸的反应。考察了不同相转移催化剂的催化活性 ,催化剂用量、反应温度、反应时间、KMn O4 用量和反应体系酸碱性对反应的影响。在优化反应条件 ,即以季铵盐 A- 1为相转移催化剂 ,高锰酸钾与硝基甲苯摩尔比为 2 .5∶ 1 ,反应温度为 95°C,反应时间为 3h,在中性条件下进行反应 ,邻位、对位产物收率分别可达 95 %、92 %。实验表明 ,季铵盐 A- 1对于高锰酸钾氧化硝基甲苯合成硝基苯甲酸的反应 ,是一种优良的相转移催化剂 相似文献
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以油酸为原料,过氧化氢和臭氧联合氧化法合成了壬二酸,并对影响反应活性的因素进行了研究,具体包括过氧化氢的浓度、用量,臭氧的浓度及通入时间,不同种类钨化合物与季铵盐组成的相转移催化体系.实验结果表明当反应温度为70℃,通入臭氧时间8 h,在合适的催化剂及原料配比情况下,壬二酸的得率为71%. 相似文献
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以正硅酸乙酯为硅源,利用溶胶-凝胶法制备了二氧化硅载过氧磷钨酸季铵盐催化剂,对催化剂进行了XRD分析。以双氧水为氧化剂,苯并噻吩(BT)和二苯并噻吩(DBT)为模型化合物,初步评价了催化剂的氧化脱硫反应性能,并考察了反应时间、催化剂用量以及反应温度等反应条件对BT和DBT的氧化脱除效果的影响。结果表明:常压下,反应温度70℃,反应时间60 min,催化剂用量(w)4%,过氧化氢和模拟油体积比1∶10的条件下,对苯并噻吩和二苯并噻吩的脱除效果最好,脱除率分别达到93.75%和97.13%。催化剂可回收多次使用,仍保持较高活性。 相似文献
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研究了以十聚钨酸季铵盐为催化剂、30%过氧化氢为氧源催化氧化苯甲醇合成苯甲醛的反应,考察了不同催化剂的催化效果、反应温度、反应时间、十聚钨酸季铵盐的用量和过氧化氢的用量等对苯甲醇选择性催化氧化反应的影响。结果表明,以十聚钨酸季铵盐([BunPy]4W10O32)为催化剂,在60℃,十聚钨酸季铵盐用量为0.08mmol,反应15h,30%过氧化氢用量为45mmol,苯甲醇的用量为30mmol时,苯甲醇的转化率为96.7%,苯甲醛的选择性达到91.5%。 相似文献
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KINETIC STUDY OF THE PHASE TRANSFER CATALYTIC EPOXIDATION OF DICYCLOPENTADIENE IN A TWO-PHASE MEDIUM
The epoxidation of dicyclopentadiene catalyzed by quaternary ammonium salt in the presence of hydrogen peroxide, sodium tungstate, and phosphoric acid was successfully carried out in an acidic aqueous solution/organic solvent two-phase medium. The epoxidation of dicyclopentadiene is dramatically enhanced in the presence of quaternary ammonium salt, hydrogen peroxide, sodium tungstate, and phosphoric acid of appropriate quantities. Based on the experimental results, a rational reaction mechanism was proposed and a pseudo steady-state hypothesis was applied to describe the kinetic data. The organic-phase reactions were found to be the rate-determining step of the entire phase transfer catalysis. Four reactions, which include the epoxidation of two single-site double bonds and one two-site double bond of dicyclopentadiene molecule, were obtained, i.e., two primary and two secondary sequential reactions in the organic phase. The purpose of this work is to investigate the effects of the reaction conditions such as agitation speed, quaternary ammonium salt, amount of Aliquat 336 catalyst, sodium tungstate, phosphoric acid, active catalyst, hydrogen peroxide, pH value, organic solvents, volume of chloroform, and temperature on the conversion of dicyclopentadiene. The apparent rate constants of the two primary reactions in the organic phase were determined. 相似文献
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国外过氧化氢在化学合成中应用研究进展 总被引:2,自引:0,他引:2
胡长诚 《化学推进剂与高分子材料》2003,1(6):1-4
介绍了近期国外过氧化氢在部分化学品合成中应用研究新进展 ,产品包括过碳酸钠、过碳酰胺、4Na2 SO4·2H2 O2 ·NaCl加合物、叔胺氧化物、水合肼、二羟基苯、季铵盐过氧化氢和甲乙酮肟。内容涉及产品质量 (纯度、安定性、溶解速率、外观等 )、产品收率、催化剂、工艺过程等方面改进。主要介绍专利技术。 相似文献
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以1,2-二氯乙烷和诺氟沙星为原料,TEBAB(三乙基丁基溴化铵)为相转移催化剂合成一种新型的、未见报道的诺氟沙星N-4′位氯乙基化衍生物,并测试了其抗菌活性。考察了反应温度、物料比和反应时间对该合成反应产率的影响。实验表明,当反应温度为70℃,n(诺氟沙星)∶n(二氯乙烷)=1.0∶1.4、反应时间为3h时,相转移催化剂TEBAB为0.2g,NaOH溶液质量分数5%,反应产率为72%左右。测试了新型的季铵盐类相转移催化剂TEBAB的活性。实验证明,新型季铵盐类相转移催化剂TEBAB的催化效果较好,活性较强。最后,经熔点测定和红外光谱表征确证合成产物为目的物,且产品抗菌活性较诺氟沙星有所提高。 相似文献
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相转移催化法制备3,4-环氧基环己基甲酸-3’,4'-环氧基环己基甲酯 总被引:1,自引:0,他引:1
采用磷钨杂多酸季铵盐为相转移催化剂,以过氧化氢为氧源,由3一-环己烯甲酸-3'-环己烯甲酯(简称A)环氧化反应合成3,4-环氧基环己基甲酸-3’,4'-环氧基环己基甲酯(简称AOO)。考察了溶剂的种类、催化剂用量(质量)、反应物料比、反应温度、反应时间等因素对反应的影响。得到了适宜的合成反应条件,即以60mmol A计,1,2-二氯乙烷30mL,nA:nH2O2=1:2.5,催化剂质量1.4g,温度65℃,时间60min。在该反应条件下,A的平均转化率在99%以上,产品AOO的平均产率为93.5%。产物经红外光谱、质谱分析证实为目标产物。 相似文献
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Water soluble, photocrosslinkable prepolymers were synthesized from epoxy phenolic resin (epoxy novolak resin) via ring‐opening reaction with acrylic acid, followed by ring‐opening reaction with aqueous solution of triethylamine hydrochloride. No phase transfer catalyst was needed to accelerate the second reaction, since the product formed can act as a phase transfer catalyst. The prepolymer obtained contains both photocrosslinkable acrylate groups and hydrophilic quaternary ammonium salt groups. Optimum conditions for these reactions were studied. The photosensitive properties of the prepolymer were also investigated. The effect of different photoinitiators, different crosslinkable diluent monomers and amine accelerator on the photosensitive properties of the prepolymer were compared. The photoinitiator of hydrogen abstraction type is still effective without using amine or alcohol as accelerator, because the prepolymer contains αH beside the OH groups formed in the ring‐opening reactions. 相似文献