共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
报道了丙硫菌唑中间体2-(2-氯苄基)-2-(1-氯环丙基)环氧乙烷的合成方法。以1-氯-N,N-二甲基环丙基甲酰胺和邻氯氯苄为原料,经格氏反应制备2-氯苄基-(1-氯环丙基)酮;后者再与硫叶立德试剂反应得到相应的环氧化物。 相似文献
3.
4.
丙硫菌唑的合成报道方法均是以邻氯苄氯为原料, 制备格氏试剂后, 经加成、缩合、硫化得到产物。由于邻氯苄氯反应活性高, 得到的格氏产物收率低, 大量偶联副产物生成, 难以工业化应用。选择环丙基苄基甲酮为原料合成丙硫菌唑的中间体, 以简便高效的中间体制备方法为目的, 研究了酸与酯经缩合反应得到酮的制备方法。经反应工艺条件优化, 在异丙基氯化镁格氏试剂存在下, 以四氢呋喃为反应溶剂, 邻氯苯乙酸和1-氯环丙基甲酸甲酯为原料, n(氯代异丙烷)/n(1-氯环丙基甲酸甲酯)为3.0, 邻氯苯乙酸与1-氯环丙基甲酸甲酯的投料比为1.1 :1.0(摩尔比), 合成得到环丙基苄基甲酮。蒸馏纯化后产品液相色谱检测纯度为98.2%, 收率为83%。该工艺收率高, 操作简单, 条件温和, 适合工业化生产。 相似文献
5.
6.
7.
8.
9.
放射性^99mTc标记的NMDA受体配基N2S2-Memantine的合成 总被引:9,自引:1,他引:8
以美金刚胺为原料,先与氯乙酰氯反应,再与二硫二氮缩合,最后与醋酸汞硫化氢反应脱巯基保护基得到标记前体N-[2-(N-(2-巯基乙基))氨基甲酰甲基J-N-(2-巯基乙基)-3,5-二甲基金刚烷胺基乙酰胺.关键化合物N-[2-((2-(S-(4-甲氧基苄基)巯基)乙基)氨基)乙酰基]-S-(4-甲氧基苄基)-2-氨基乙硫醇和N-[2-(S-(4-甲氧基苄基)硫基)乙基]-N-[N-(2-(S-(4-甲氧基苄基)硫基)乙基)氨基)甲酰甲基]-3,5-二甲基金刚烷胺基乙酰胺得到核磁和质谱表征,总收率为32%. 相似文献
10.
N-甲基-N-(4′-氨基苄基)-4-甲苯磺酰胺的合成包括三步反应,首先由对甲苯磺酰氯与甲胺反应得到N-甲基-4-甲基苯磺酰胺,再与对硝基苄基溴反应引入苄基,然后在铁催化剂存在下用水舍肼将硝基还原,得到N-甲基-N-(4′-氨基苄基)-4-甲苯磺酰胺;该工艺重现性好,三废少,三步反应总收率81%。得到的N-甲基-N-(4′-氨基苄基)-4-甲苯磺酰胺与溴胺酸反应即得C.I.酸性蓝264,该染料染色时对染浴的pH不敏感、竭染率高、水洗牢度好。 相似文献
11.
12.
M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
13.
Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
14.
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. 相似文献
15.
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. 相似文献
16.
17.
18.
19.
20.
Peter A. Edwards Grant Striemer Dean C. Webster 《Journal of Coatings Technology and Research》2005,2(7):517-527
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. 相似文献