2-溴-3-乙磺酰基吡啶的合成

2-溴-3-乙磺酰基吡啶是磺酰脲类除草剂玉嘧磺隆重要中间体.以乙磺酰基乙腈和1,1,3,3-四甲氧基丙烷为起始原料,经取代、环合反应合成得到目标产物.含量≥95.0%,收率75.5%(以乙磺酰基乙腈计).     

新型除草剂玉嘧磺隆的合成研究

玉嘧磺隆是磺酰脲类除草剂。以乙磺酰基乙腈和1,1,3,3-四甲氧基丙烷为起始原料,经消除加成、取代、环合、硫代、磺酰胺化、缩合六步反应合成得到玉嘧磺隆,总收率(以乙磺酰基乙腈计)38.8%,含量大于98.5%。产物及中间体结构经1HNMR、MS表征,结构正确。     

相转移催化法合成2-甲氧基-5-乙磺酰基苯甲酸

以4－甲氧基－3－羧基苯磺酰氯为原料，用相转移催化方法合成盐酸舒托必利中间体2－甲氧基－5－乙磺酰基苯甲酸，工艺简便，条件温和。 总收率54％。     

磺酰磺隆的合成

[目的]寻找具有工业化前景的除草剂磺酰磺隆的合成工艺。[方法]以2-氯咪唑[1,2-a]吡啶-3-磺酰胺为起始原料,先与乙硫醇钠反应合成2-乙硫基咪唑[1,2-a]吡啶-3-磺酰胺,再与双氧水反应合成2-乙磺酰基咪唑[1,2-a]吡啶-3-磺酰胺,最后与N-(4,6-二甲氧基嘧啶基-2-基)氨基甲酸苯酯反应合成磺酰磺隆。[结果]通过实验,确定了最佳路线,3步反应总收率68.1%,含量98.2%(HPLC)。[结论]该合成工艺具有步骤少、收率高、安全可靠的特点,可为工业化生产提供参考。     

除草剂噻磺隆的合成

报道了以氯甲酸甲酯和2-甲氧羰基-3-氨基磺酰基噻吩为起始原料合成除草剂噻磺隆的方法。原料2-甲氧羰基-3-氨基磺酰基噻吩与氯甲酸甲酯生成2-甲氧羰基-3-甲氧羰基氨基磺酰基噻吩,再与2-氨基-4-甲氧基-6-甲基均三嗪反应生成噻磺隆。避免了异氰酸酯路线的种种缺点,具有收率高、含量高、成本低的特点。以2-甲氧羰基-3-氨基磺酰基噻吩计,总收率为77.73%,原药纯度达93.6%。     

2-氯-3-乙磺酰基吡啶合成方法的改进

2-氯-3-乙磺酰基吡啶是合成砜嘧磺隆的中间体,目前合成该中间体的路线较多,但收率均不高。以巯基乙腈为起始原料,经4步反应合成了中间体2-氯-3-乙磺酰基吡啶。该路线原料易得,操作方便,易于工业化生产。     

新型玉米田除草剂甲基磺草酮的合成研究

以2-硝基-4-甲磺酰基一笨甲酰氯和1，3-环己二酮为原料，首先碱性条件下合成烯醇酯，然后再经催化重排制得甲基磺酮，讨论了反应条件对产品收率的影响并得到了适宜的工艺条件。结果表明，在以二氯甲烷为溶剂，三乙胺为缚酸剂，重排温度为50℃时，所得甲基磺草酮产品含量≥95．0％，收率≥70．0％。     

创新工艺

1-氯甲酰基-3-甲磺酰基-2-咪唑烷酮的化学合成方法浙江工业大学的研究人员研究了1-氯甲酰基-3-甲磺酰基-2-咪唑烷酮的化学合成方法：以有机碱为捕酸剂，以双（三氯甲基）碳酸酯和1-甲磺酰基-2-咪唑烷酮为原料在有机溶剂中反应制得。该产品是新型半合成抗菌素——美洛西林的重要中间体。     

三光气法合成磺酰脲类除草剂的研究

利用三光气代替光气合成磺酰脲类除草剂的新方法，用该方法成功地合成了噻磺隆和苯磺隆，其中噻磺隆收率83．3％，苯磺隆为85．4％，均以对应的磺酰胺计。噻磺隆和苯磺隆的合成稳定性结果表明．效果明显优于光气法。     

除草剂砜嘧磺隆的合成研究

以乙基磺酰基乙腈和丙二醛甲醇缩醛为起始原料,经五步反应得到除草剂砜嘧磺隆,并对砜嘧磺隆和中间体2-氯-3-乙基磺酰基吡啶、2-巯基-3-乙基磺酰基吡啶以及2-磺酰胺基-3-乙基磺酰基吡啶进行了1HNMR结构表征,证实了它们的结构.     

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.     

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.     

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.