2,2＇-偶氮二异丁基脒盐酸盐的合成

以偶氮二异丁腈（AIBN）为主要原料,经Pinner反应制备了2,2＇-偶氮二异丁亚胺甲醚盐酸盐,再进一步合成2,2＇-偶氮二异丁基脒盐酸盐。最佳合成工艺条件为n（AIBN）：n（甲醇）：n（氯化氢）=1：2.5：2.6,反应温度15～20℃,反应时间24h,得到2,2＇-偶氮二异丁亚胺甲醚盐酸盐,收率99.1%;以无水甲醇为溶剂,与氨气反应合成了2,2＇-偶氮二异丁脒盐酸盐,反应温度10～15℃,反应时间16h,收率85.1%,纯度≥99.5%。产物用红外光谱、核磁共振等进行了确证。     

2，2’-偶氮二（N-环己基异丁基脒）盐酸盐的合成

以偶氮二异丁腈为主要原料制备了2,2’-偶氮二（N-环已基异丁基脒）盐酸盐,研究了2,2’-偶氮二异丁亚胺甲醚盐酸盐及2,2’-偶氮二（N-环己基异丁基脒）盐酸盐的最佳合成工艺条件。以1,2-二氯乙烷为溶剂,n（偶氮二异丁腈）：n（甲醇）：n（氯化氢）=1：2．5：2．6,反应温度15-20℃,反应时间24h,得2,2’-偶氮二异丁亚胺甲醚盐酸盐,收率99．1％;以无水甲醇为溶剂,与环己胺反应合成了2,2’-偶氮二（N-环己基异丁基脒）盐酸盐,n（偶氮亚胺甲醚盐酸盐）：n（环己胺）=1：2．5,反应温度30-35℃,反应时间8h,收率78．2％。产物经IR和^1HNMR等进行了确证。     

2,2’-偶氮二异丁酸二甲酯的制备

以丙酮氰醇(ACH)、水合肼、Cl2、甲醇(CH3OH)和HCl为原料,经缩合、氧化、Pinner反应、水解反应制备2,2’-偶氮二异丁酸二甲酯,对反应条件进行了优化。确定反应的最佳工艺条件为n(ACH)∶n(水合肼)∶n(四甲基溴化铵)=1∶0.53∶0.0052、n(偶氮二异丁腈肼)∶n(Cl2)∶n(HCl)∶n(CH3OH)=1∶1.1∶0.8∶2.6、缩合反应温度25～30℃、反应2 h、氰醇化反应温度10～15℃、反应24 h,产品纯度在98%以上,总收率大于90%。     

偶氮二异丁酸二甲酯的合成

以甲醇为溶剂,偶氮二异丁腈肼与氯气和甲醇反应,经水解、重结晶,制备出了偶氮二异丁酸二甲酯,探讨了最佳合成工艺条件：n（HAIBN）：n（Cl2）：（HCl）=1：1．3：0．8,反应温度20～25℃,反应18h,收率93．6％,含量99．3％。产物用红外光谱、核磁共振等进行了确证。     

偶氮二甲酸二甲酯合成研究

研究了以偶氮二甲酰胺为原料,水解生成偶氮二甲酸盐,滴加硫酸二甲酯生成偶氮二甲酸二甲酯的新工艺。对甲基化反应的最佳工艺条件进行了探讨,结果表明:以水作为溶剂,n(硫酸二甲酯):n(偶氮二甲酰胺)=2.4:1,反应温度为55℃,反应时间在3 h,pH值为9～10,收率达到90.9%。改进的合成工艺条件缓和操作简便、合理且可行,提高了产率。     

偶氮二异丁脒盐酸盐的合成研究

偶氮二异丁脒盐酸盐 (ＡＩＢＡ)是良好的聚合反应引发剂 ,具有制备的聚合物相对分子质量分布相对比较集中、反应速度较快等优点。研究了ＡＩＢＡ合成中的优化条件如下 :偶氮二异丁腈 10 0ｇ ,10℃下加入到 80ｍＬ无水氯化氢的醇溶液中 ,反应后冷却、过滤得烷氧基亚胺盐酸盐中间产物 19 2ｇ ,收率95 7%。通氨气反应得偶氮二异丁脒盐酸盐 14 5ｇ ,收率 87 7%。分解温度 177 4℃ ,纯度 97 5 % ,重结晶后产品纯度达到 99 99% ,分解温度 179 8℃。产品经ＩＲ、1Ｈ -ＮＭＲ(ＩＲ :ＢｒｕｋｅｒＶｅｃｔｏｒ 2 2型傅立叶红外变换光谱仪 ;1Ｈ -Ｎ…     

间硝基苯甲醛的合成工艺研究

以间硝基甲苯为原料,以AIBN(偶氮二异丁腈)为催化剂合成间硝基苯甲醛。在n(间硝基甲苯)∶n(氯溴酸)∶n(双氧水)=1∶3∶3,溴化温度65～75℃,溴化时间8～9h,氧化水解时间在8h的优化条件下,产品收率30.4%,纯度99.2%。     

一种水溶性偶氮类引发剂的合成

合成了一种水溶性偶氮引发剂——偶氮二异(N-胺乙基)丁脒,讨论了工艺条件对反应收率的影响,得到其最佳合成工艺条件为反应温度30℃左右,偶氮亚氨甲醚盐酸盐溶液浓度为0.25 mol/L,乙二胺与偶氮亚氨甲醚物质的量比为1.2,反应时间9 h。并研究其热分解反应动力学,得到分解反应级数符合一级反应动力学规律,热分解反应活化能为88 kJ/mol。将此引发剂用于烯丙基胺盐酸盐的聚合得到特性粘数为13.74 mL/g(30℃)的聚合物。     

98%甲基嘧啶磷合成新工艺研究

在水解抑制剂及氢氧化钠的作用下,2-二乙基氨基-6-甲基-4-羟基嘧啶与O,O-二甲基硫代磷酰氯反应制备甲基嘧啶磷,优化工艺条件为:原料配比n(嘧啶醇)∶n(甲基氯化物)∶n(氢氧化钠)∶n(水解抑制剂)=1∶1.05∶1.2∶0.263,反应温度20~40℃,反应时间3h。此条件下产品收率94%,产品含量99%。     

两步法合成间硝基苯甲醛

间硝基甲苯与双氧水、氢溴酸在AIBN作用下,生成间硝基一溴苄和二溴苄,再经DMSO、二甲胺氧化水解生成间硝基苯甲醛。研究了溴化、氧化水解反应的影响因素,优化了反应条件。结果表明,溴化反应较佳的条件为:溴化温度60℃,溴化时间4 h,n(间硝基甲苯)∶n(氢溴酸)∶n(双氧水)=1∶2.5∶2.5,AIBN用量0.8 g;氧化水解反应较佳的条件为:氧化温度105℃,保温时间8 h,水解温度60℃,水解时间1 h。在该条件下,间硝基苯甲醛收率达58.6%,色谱纯度达99.1%。通过IR和1HNMR对产物结构进行了表征。     

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.     

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.     

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.