三相相转移催化合成仲丁基二硫醚

以仲丁基溴(RBr)、升华硫、九水硫化钠为原料,采用自制的SiO2-g-PS负载季铵盐为三相相转移催化剂合成二仲丁基二硫醚。通过正交实验得到最佳工艺条件为:n(Na2S)∶n(RBr)=1∶0.8,催化剂质量分数为0.75%,反应温度为30℃,反应时间为9 h。在该条件下重复3次实验,平均收率为57.65%。与其他三相催化剂相比,该催化剂催化效果最好,且重复使用6次活性并未明显降低,产物结构经1HNMR和FTIR确证。     

2，6-二叔丁基对仲丁基酚的合成

以磺酸阳离子树脂为催化剂,以对仲丁基苯酚和异丁烯为原料合成了2,6-二叔丁基对仲丁基苯酚。探讨了不同催化剂、反应温度、反应时间、物料配比和催化剂用量对反应的影响。最优的反应条件:催化剂的质量分数为3%～5%(以对仲丁基苯酚质量计,下同),n(对仲丁基苯酚)∶n(异丁烯)=1∶2,反应温度90～100℃,反应压力0.15～0.2 MPa,反应时间4 h,在该条件下,产物选择性达95%以上,精馏分离得到色谱纯度大于97.5%的2,6-二叔丁基对仲丁基苯酚,总收率达95%以上。     

一步催化硝化法制备DNBP

提出了以甲基磺酸作催化剂在硝酸中一步硝化邻仲丁基苯酚制取邻仲丁基-4,6-二硝基苯酚(DNBP)的新工艺.通过单因素实验确定最佳的合成工艺条件如下:n(邻仲丁基苯酚):n(硝酸)=1:3.0、ω(硝酸)=50%、甲基磺酸用量为10%(以邻仲丁基苯酚质量计)、反应时间为4 h、反应温度为45℃,此时DNBP产率达86.8%、纯度高于98.5%.利用红外光谱和质谱对产物进行结构分析,表明该产品为目的产物.     

TiSiW12O40/SiO2催化合成2,4-二甲基-2-(4-甲基-3-戊烯基)-1,3-二氧六环的研究

以6-甲基-5-庚烯-2-酮和1，3-丁二醇为原料，采用TiSiW12O40／SiO2作催化剂，研究了合成环缩酮香料化合物2，4-二甲基-2-(4-甲基-3-戊烯基)-1，3-二氧六环的反应条件。实验结果表明，优化反应条件为：n(6-甲基-5-庚烯-2-酮)：n(1，3-丁二醇)=1．0：1．1，催化剂用量为3％(占6-甲基-5-庚烯-2-酮的质量分数)，反应时间4h，2，4-二甲基-2-(4-甲基-3-戊烯基)-1，3-二氧六环的产率为96．5％。催化剂无需处理可直接重复使用8次以上。     

活性炭负载钛酸四丁酯催化合成二甘醇二苯甲酸酯

以活性炭负载钛酸四丁酯[Ti(OBu)4/AC]为催化剂,用于催化合成二甘醇二苯甲酸酯（DEDB）。通过实验确定了合成DEDB的适宜工艺条件：n(BA)∶n(DEG) = 2∶1、催化剂用量为1.25%,带水剂用量为20.0%,反应温度为200℃,反应时间为7h,该反应条件下酯化率可达98.1%。催化重复使用实验表明该催化剂具有良好的稳定性。同时建立了该酯化合成的表观动力学模型,得到反应速率方程为：rA=6.28× 109exp CACB。     

一步反应法制备乙酰丙酮的工艺研究

研究以乙酰乙酸乙酯和乙酸酐为原料、一步反应法合成乙酰丙酮的工艺。通过单因素实验、正交实验、二次拟合法得最佳工艺参数为反应时间15.3h、原料配比n(乙酰乙酸乙酯)∶n(Ac2O)为1∶1,催化剂用量为Ac2O质量的3%。在此条件下进行实验,乙酰丙酮收率99.28%,纯度为99.27%。     

固体超强酸SO42-/TiO2-Al2O3-SnO2催化合成DBS

以固体超强酸SO4^2-／TiO2-Al2O3-SnO2为催化剂、葵二酸和正丁醇为原料合成了癸二酸二丁酯(DBS)。研究了反应时间、醇酸物质的量比、催化剂用量等对酯化率的影响。结果表明：最佳反应条件为以0.05mol葵二酸为基准，n(酸)：n(醇)=1：4，催化剂0．5g，反应时间3．5h，此时酯化率达97．5％，产品质量分数大于98％；催化剂重复使用6次后，催化活性基本不变。     

磷钨钼酸催化合成4-苯基-6-甲基-5-乙氧羰基-3，4-二氢嘧啶-2（H）-酮

以磷钨钼杂多酸为催化剂，无水乙醇为溶剂，苯甲醛、乙酰乙酸乙酯、尿素为原料，合成了4-苯基-6-甲基-5-乙氧羰基-3，4-二氢嘧啶-2（H）-酮，系统研究了催化剂用量、反应温度、反应时间、原料配比诸因素对产品收率的影响。实验表明：磷钨钼杂多酸是合成4-苯基-6-甲基-5-乙氧羰基-3，4-二氢嘧啶-2（H）-酮的良好催化剂。确定的最优合成工艺条件为：尿素37．5mmol时，n（苯甲醛）：n（乙酰乙酸乙酯）：n（尿素）=1：1．2：1．5，催化剂用量为反应物料总质量的1．5%，反应温度为60℃，反应时间1．0h。在此条件下，产品收率可达44．6%.     

玻璃珠载固体超强酸SO_4~(2-)/TiO_2催化合成二甘醇二苯甲酸酯

以玻璃珠为载体,制备了固体超强酸SO42-/TiO2催化剂,用于催化合成二甘醇二苯甲酸酯(DEDB)。通过实验确定了合成DEDB的适宜工艺条件:回流温度为165~170℃,m(甲苯)/m(二甘醇)=0.5,n(苯甲酸)/n(二甘醇)=2.2,m(催化剂)/m(二甘醇)=0.5,反应时间4 h,在该条件下,酯化率可达99.6%。该催化剂经过10次重复使用,活性每次平均下降2.9%。     

N－硬脂酰基－N’，M’－二甲基丙二胺的合成

以硬脂酸和N，N-二甲基丙二胺为原料、二甲苯为溶剂、有机锡为催化剂合成了抗静电剂CyastatSN的中间体-N-硬脂酰基-N’，N’-二甲基丙二胺。通过正交实验确定了最佳工艺条件，分别为：物料配比n硬脂酸：n胺=1：1，反应温度为145℃，反应时间为2h，催化剂用量为(硬脂酸与胺总量)3％(质量分数)。最优条件下的试验收率近90％，并对中间体进行了IR光谱分析及纯度测定。     

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.     

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.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.