2,4,6-三硝基氯苯合成工艺研究

2,4,6-三硝基氯苯是一种重要的医药和化工中间体,也是合成新型耐热炸药的重要原料。以2,4-二硝基氯苯为原料,浓硫酸与发烟硝酸体系为硝化试剂制备得到2,4,6-三硝基氯苯,并利用红外(IR)、核磁共振(NMR)、质谱(MS)等对产物进行了表征。研究了物料配比、反应温度、时间对硝化反应收率的影响,确定了优化的工艺条件:n(发烟硝酸)∶n(2,4-二硝基氯苯)=4.76∶1,n(浓硫酸)∶n(发烟硝酸)=4.0∶1,反应温度为130℃,反应时间为7 h时,2,4,6-三硝基氯苯收率可达到84.4%,熔点为82.8℃,液相色谱分析纯度为93.4%。     

2,4,6-三硝基氯苯合成工艺研究

2,4,6-三硝基氯苯是一种重要的医药和化工中间体,也是合成新型耐热炸药的重要原料。以2,4-二硝基氯苯为原料,浓硫酸与发烟硝酸体系为硝化试剂制备得到2,4,6-三硝基氯苯,并利用红外(IR)、核磁共振(NMR)、质谱(MS)等对产物进行了表征。研究了物料配比、反应温度、时间对硝化反应收率的影响,确定了优化的工艺条件:n(发烟硝酸)∶n(2,4-二硝基氯苯)=4.76∶1,n(浓硫酸)∶n(发烟硝酸)=4.0∶1,反应温度为130℃,反应时间为7 h时,2,4,6-三硝基氯苯收率可达到84.4%,熔点为82.8℃,液相色谱分析纯度为93.4%。     

氟双相体系中甲苯硝化反应的研究

以全氟己烯(PFH)为氟溶剂,混酸为硝化剂,在氟双相体系中对甲苯进行硝化。实验表明:在反应温度为50℃,n(甲苯)∶n(硝酸)=1∶1.05,m(全氟己烯)∶m(甲苯)=1∶1.8,反应时间为4h,甲苯的转化率达99.5%,产品硝基甲苯总质量分数为98.3%,邻对位异构体质量比为1.51,硫酸、氟溶剂很容易通过相分离而得到回收利用。     

p-全氟壬烯氧基苯甲酸芝麻酚酯的合成

以p-全氟壬烯氧基苯甲酰氯(Ⅰ)和芝麻酚(Ⅱ)为原料,经酯化反应,制备p-全氟壬烯氧基苯甲酸-3,4-亚甲二氧基苯基酯(Ⅲ),用FTIR、1HNMR、19FNMR对其结构进行了表征。考察了缚酸剂、反应温度、反应时间、原料配比对酯化反应收率的影响。优化了酯化反应工艺,得到合成p-全氟壬烯氧基苯甲酸-3,4-亚甲二氧基苯基酯较佳的工艺条件为:二甲基甲酰胺(DMF)为溶剂,三乙胺(NEt3)为缚酸剂,n(Ⅰ)∶n(Ⅱ)∶n(NEt3)=1∶2∶1,-5℃反应4 h,在该条件下收率达79.0%。     

3,5-二硝基吡唑的合成工艺研究

以3-硝基吡唑为原料,经过发烟硝酸-乙酸酐体系硝化、邻二氯苯重排、乙醚提纯制备3,5-二硝基吡唑。考察了硝化和重排两步反应的条件,得出硝化的最佳工艺条件为:n(3-硝基吡唑)∶n(发烟硝酸)∶n(乙酸酐)=1∶1.5∶2.25,反应温度50℃,反应时间4 h,得率85.9%;重排工艺的最佳工艺条件为:重排试剂为邻二氯苯,重排温度为170℃,重排时间8 h,乙醚对重排产物提纯,得率78.3%。用较佳的高效液相色谱条件对工艺中各产物的纯度进行了鉴定。     

3,5-二硝基吡唑的合成工艺研究

以3-硝基吡唑为原料,经过发烟硝酸-乙酸酐体系硝化、邻二氯苯重排、乙醚提纯制备3,5-二硝基吡唑。考察了硝化和重排两步反应的条件,得出硝化的最佳工艺条件为:n(3-硝基吡唑)∶n(发烟硝酸)∶n(乙酸酐)=1∶1.5∶2.25,反应温度50℃,反应时间4 h,得率85.9%;重排工艺的最佳工艺条件为:重排试剂为邻二氯苯,重排温度为170℃,重排时间8 h,乙醚对重排产物提纯,得率78.3%。用较佳的高效液相色谱条件对工艺中各产物的纯度进行了鉴定。     

邻硝基对甲苯胺的合成

以对甲苯胺为原料,合成了邻硝基对甲苯胺(红色基GL)。改进了合成工艺,将酰化、硝化、水解三步合为一锅反应,总收率可达88.8%。用发烟硝酸硝化,加入二氯乙烷作溶剂,溶剂可回收利用。通过实验确定了物料的最佳配比为:n(对甲苯胺)∶n(乙酐)=1∶1.15,n(对甲苯胺)∶n(发烟硝酸)=1∶2.6,二氯乙烷的用量为105 mL(0.1 mol对甲苯胺)。     

4,5-二甲基-1,2-二苯胺的合成工艺改进

以3,4-二甲基苯胺为原料,合成了4,5-二甲基-1,2-二苯胺,产品收率达69%以上。在乙酰化、硝化反应中引入了1,2-二氯乙烷溶剂。用正交实验确定了最佳原料配比:n(3,4-二甲基苯胺)∶n(醋酸酐)∶n(硫酸)=1.00∶1.15∶1.10,硝化反应温度为13°C,反应时间为3.5h,硝化产物收率为90.56%,溶剂回收率95%以上。改进后,每摩尔母体的醋酸酐用量由303g减少至118g,浓硫酸用量由304g减少至108g。     

2,7-二溴-N-辛基咔唑的合成与表征

以4,4'-二溴联苯为原料,经硝化、闭环、N-烷基化反应合成了2,7-二溴-N-辛基咔唑(Ⅲ)。4,4'-二溴联苯与发烟硝酸按n(4,4'-二溴联苯)∶n(HNO3)=1.0∶4.0,在75℃下进行硝化,反应5 h,得到了2-硝基-4,4'-二溴联苯(Ⅰ),收率97%;中间产物Ⅰ与三苯基膦按n(2-硝基-4,4'-二溴联苯)∶n(三苯基膦)=1.0∶3.0,在无水无氧条件下,闭环反应得到了2,7-二溴咔唑(Ⅱ),收率85%;在碱性条件下,中间产物Ⅱ与1-溴辛烷按n(2,7-二溴咔唑)∶n(1-溴辛烷)=1.0∶1.5,N-烷基化反应合成最终产物,收率85%。产物结构经IR、元素分析和1HNMR确证。     

微反应器合成1,2,4-丁三醇三硝酸酯的工艺研究

以1,2,4-丁三醇(BT)水溶液为起始原料,发烟硝酸/浓硫酸为硝化剂,采用微反应器连续合成1,2,4-丁三醇三硝酸酯,考察反应温度、物料及混酸比例、停留时间对反应影响.结果表明,优化工艺参数为:1,2,4-丁三醇:发烟硝酸:浓硫酸的摩尔比为1:5:4,反应温度15℃,停留时间48 s,工艺收率90.5％,产品含量98...     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

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.