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1.
李群  周丽娜  林润雄 《应用化工》2011,40(4):642-644
以五溴甲苯和溴为原料,合成了五溴苄基溴。考察了原料配比、反应温度及反应时间对反应收率的影响,确定的最佳反应条件为:n(溴)∶n(五溴甲苯)=1.4∶1,反应温度80℃,反应时间2 h,收率达88.5%。并用IR,1HNMR和DSC对产物结构进行了表征。  相似文献   

2.
溴系阻燃剂五溴甲苯的合成新工艺研究   总被引:1,自引:0,他引:1  
由甲苯经溴化制得五溴甲苯,重点考察了催化剂掺杂质量比、催化剂的用量、原料配比、反应时间等工艺参数对合成产物的影响.实验结果表明,m(Bu2SnCl2):m(AlCl3)=1:1作为复合催化剂,对合成五溴甲苯有着良好的催化活性,当m(复合催化剂):m(甲苯)=0.05,n(甲苯):n(溴)=1:7.5,n(溶剂CCl4)...  相似文献   

3.
高春香  张静  王蕾 《当代化工》2007,36(2):136-138
以对溴甲苯为原料、四氯化碳为溶剂进行溶剂光溴化合成对溴苄基溴,考察了配比、反应时间对反应的影响,得出了最适宜的工艺条件:n(对溴甲苯)∶n(溴)=1∶0.98 、反应时间5.5 h,并采用甲醇淋洗和乙醇重结晶的后处理方法处理反应产物,所得产品纯度99 %,收率60 %左右.  相似文献   

4.
室温下,在二氯甲烷溶剂中,用三溴化硼溴化4-溴甲苯甲基侧链,合成了4-溴溴苄,收率84.4%;无水乙醇回流条件下,物料比n(4-溴溴苄)∶n(吡啶)=1∶1时,合成溴化N-(4-溴苄基)吡啶,收率95.3%;物料比n(溴化N-(4-溴苄基)吡啶)∶n(丙二腈)=2∶1时,合成2,2-二(4-溴苄基)丙二腈,收率67.0%;二氯亚砜催化2,2-二(4-溴苄基)丙二腈在有水的条件下醇解合成2-氰基-2,2-二(4-溴苄基)乙酸乙酯,收率65.3%。  相似文献   

5.
以10-十一烯酸和溴化氢为原料合成11-溴代十一酸,考察了引发剂、溶剂、反应温度、后处理方法、熟化时间等因素对反应和产品的影响。结果表明,较佳的工艺条件为:以n(苯)∶n(甲苯)=1∶0.83的苯/甲苯混合物作为溶剂,m(10-溴代十一酸)∶m(溶剂)=1∶4,引发剂为过氧化苯甲酰,反应温度为5~20℃,熟化时间为6 h。在此工艺条件下,11-溴代十一酸的收率可达91%。  相似文献   

6.
对以邻硝基甲苯为原料,NaBrO3/NaHSO3为溴化剂,偶氮双异丁腈(AIBN)为引发剂,制备邻硝基苄基溴的工艺路线进行了研究,在优惠的工艺条件下n(邻硝基甲苯)∶n(溴酸钠)∶n(亚硫酸氢钠)=1∶4∶4,反应温度70℃,时间2h,反应收率≥73%。该工艺具有生产成本低、操作简便和易于工业化生产等特点。  相似文献   

7.
以对甲基苯甲酸和N-溴代丁二酰亚胺(NBS)为原料,采用过氧化苯甲酰(BPO)引发自由基反应合成对溴甲基苯甲酸。采用单因素实验,考察溶剂种类及用量、原料配比、BPO的用量及反应时间对反应的影响。结果表明,最优的合成条件是:以四氯化碳为溶剂,其用量为25.0m L,反应原料的摩尔比为n(NBS)∶n(对甲基苯甲酸)=1.05∶1.0,引发剂的用量为NBS摩尔量的0.04倍,反应时间为2.0 h。用此法合成对溴甲基苯甲酸操作简便,工艺最优,其合成收率为78.2%。  相似文献   

8.
张书文  柏雷  侯林艳  潘玉莲  陈贺 《化学世界》2011,52(9):538-540,546
以水为溶剂,以甲苯、1-丙醇和溴为原料,采用“一锅法”在合成对溴甲苯和邻溴甲苯的同时利用甲苯溴代生成的溴化氢进一步合成了1-溴丙烷.通过实验优化并确定了反应条件,其最佳工艺条件为:反应物的摩尔比为n(甲笨):n(溴)∶n(醇)=1∶1∶0.8;甲苯溴代阶段的反应温度为20~25℃;反应时间为2.5h;对溴甲苯和邻溴甲苯...  相似文献   

9.
一锅法合成五溴苄基溴   总被引:1,自引:0,他引:1  
首次由甲苯经催化溴化制得五溴甲苯,不经分离直接在引发剂作用下进行α位甲基溴化,合成了五溴苄基溴,并对反应条件及其影响因素进行了讨论。  相似文献   

10.
无溶剂条件下,在自由基引发剂的作用下,溴化氢气体以鼓泡的方式通入到反应体系中,与1-辛烯(1-octene)发生反马氏加成,得到目标产物1-溴代正辛烷。考察了引发剂的种类、溶剂、反应温度、反应时间、投料比和反应前活化温度等对收率的影响。结果表明,以过氧化苯甲酰(BPO)作引发剂、反应温度20℃、反应1.5 h、n(1-辛烯)∶n(溴化氢)=1.0∶1.2、无溶剂条件下,产品收率大于80%,蒸馏后纯度大于99%。  相似文献   

11.
Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.  相似文献   

12.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  相似文献   

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Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.  相似文献   

18.
收集了2007年7月~2008年6月世界塑料工业的相关资料,介绍了2007~2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.  相似文献   

19.
收集了2005年7月~2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。  相似文献   

20.
Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.  相似文献   

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