间氯三氟甲苯的合成

催化剂FeCl3／I2与催化剂FeCl3／Fe催化氯化三氟甲苯合成了间氯三氟甲苯，比较了两种催化剂的活性，并研究了反应温度、转化率对间氯三氟甲苯选择性的影响。     

液相氧化间氯甲苯合成间氯苯甲酸

在醋酸溶液中,醋酸钴为催化剂,以间氯甲苯、氧气为原料合成间氯苯甲酸,分别研究了反应温度、反应时间、原料配比、催化剂的用量等条件对合成反应的影响,确定了最佳工艺条件。该方法合成间氯苯甲酸的最适宜的操作条件是:反应温度为100℃、反应时间为12 h、n(间氯甲苯)∶n(醋酸)=1∶3、催化剂的用量为0.03 mol(相对于0.2 mol间氯甲苯)。间氯苯甲酸的收率可达到95.17%以上,间氯苯甲酸产品纯度99.5%。     

TiO2负载Pd-Fe催化剂常压氢化间硝基三氟甲苯的研究

研究了以TiO2负载Pd-Fe作催化剂,间硝基三氟甲苯常压加氢制备间三氟甲基苯胺,探讨了反应时间、溶剂及其用量、反应温度和催化剂用量等因素对加氢反应的影响,用元素分析、IR和 1HNMR对产物的结构进行了表征.优化反应条件为:催化剂用量为2.6 g/mol硝基物,无水乙醇作溶剂,用量为0 .8 L/mol硝基物,反应温度为50 ℃,0.1 MPa下加氢反应2 h,产率97.7%,目标产物的纯度达99.2%,催化剂可以重复使用10次.     

2-氟-6-三氟甲基苯磺酰氯的合成工艺研究

以间氟三氟甲苯为原料,采用邻位锂化法合成了2-氟-6-三氟甲基苯磺酰氯。通过单因素试验确定了反应的工艺条件。优化后的反应条件为:锂化反应以n-BuLi作为反应的碱,锂化反应温度-50℃,n(间氟三氟甲苯)∶n(n-BuLi)=1∶1;酰氯化反应温度-30℃,n(间氟三氟甲苯)∶n(SO2Cl2)=1.0∶1.2。经优化后,反应收率为86.8%,气相色谱检测产品含量为98.2%。该方法具有收率高、操作简单的特点,适合于工业生产。     

3,4,5-三甲基叔丁基苯的合成与分析

介绍了以连三甲苯和氯代叔丁烷为起始原料 ,在自制的非均相催化剂W 1 0 0作用下一步合成3,4 ,5 -三甲基叔丁基苯的简便方法。经探索性试验、正交试验和单因素试验确定了最佳反应条件 :连三甲苯与氯代叔丁烷物质的量比为n连三甲苯∶n氯代叔丁烷 =1∶1 ,催化剂W 1 0 0的用量占连三甲苯的质量分数为 2 % ,反应温度 5℃ ,反应时间 7～ 8h ,在此条件下 ,3,4 ,5 -三甲基叔丁基苯的收率达到 79%以上     

七氟醚合成工艺的改进

以六氟异丙醇、多聚甲醛和三氯化铝为原料在催化剂的作用下反应得到氯甲基2,2,2-三氟-1-(三氟甲基)乙基醚,再与氟化钾反应合成七氟醚。最佳原料配比为:六氟异丙醇∶多聚甲醛∶三氯化铝∶氟化钾=1∶1∶1.1∶2(摩尔比)。合成氯甲基-1,1,1,3,3,3-六氟异丙基醚的最佳反应温度为30℃。七氟醚的最佳反应时间为12 h,最佳反应温度为80℃。考察了反应时间、反应温度、催化剂用量等对反应的影响,七氟醚的纯度达到99.3%(GC),收率达到70.4%。     

间氯三氟甲苯硝化反应工艺条件优化研究

通过均匀试验和单纯形优化法,得到由问氯三氟甲苯硝化制备5-氯-2-硝基三氟甲基苯的最优化工艺条件t反应温度35℃,反应时间2．5h,硝酸与硫酸的摩尔比为1：3．5,硝酸与原料问氯三氟甲苯的摩尔比为1．15：1。在最优化工艺条件下,目标产物5-氯-2-硝基三氟甲基苯的收率为84．7％．     

对氟苯甲酰氯的合成研究

以对氟甲苯为原料，经氯化、水解、精馏制备对氟苯甲酰氯。通过对氯化反应、水解反应条件进行筛选，得出最优反应条件：（1）氯化反应时，反应温度为100～105℃，反应时间5h，抑制剂为三乙醇胺，且m（三乙醇胺）∶m（对氟甲苯）=0.7∶1000，在此条件下，反应收率98.5%;(2)水解反应时，反应温度为120℃，催化剂为三氯化铁，且n（三氯化铁）∶n（对氟三氯苄）=0.02∶1，在此条件下，反应收率98.9%。两步总收率高达97.4%。     

间羟基三氟甲苯的合成

以三氟甲苯为原料，经硝化、还原、重氮化、水解等过程，可以提到重要的农药中间体间羟基三氟甲苯，产物总收率达70％以上，在较高温度下进行重氮化反应时，可以显著提高间氨基三氟甲苯重氮化、水解反应的收率。     

间羟基三氟甲苯的合成

以三氟甲苯为原料，经硝化、还原、重氮化、水解等过程，可以得到重要的农药中间体间羟基三氟甲苯，产物总收率达70％以上，在较高温度下进行重氮化反应时，可以显著提高间氨基三氟甲苯重氮化、水解反应的收率。     

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.     

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.     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。