新型香料2,3—二甲基吡嗪的一步合成法研究[摘]

2,3二甲基吡嗪是一种新型的香料,广泛地用于饮料、糖果、肉类制品及调味品等。亦常用为烟草的加香剂。本文作者用一步法由丁二酮和乙二胺直接合成2,3—二甲基吡嗪,产率达80%,经精制后纯度达99%、b.p186℃、IR与文献记载一致。     

N—（取代苯基）吡嗪—2,3—二羧亚胺的合成及其生物活性

由不同的取代苯胺和2,3-吡嗪二羧酐(通过二氨基马来酰腈与1,2-二酮缩合制备)出发合成了84种3-[(取代苯氨基)羰基]-2-吡嗪羧酸(3)和同样数量的N-(取代苯基)吡嗪-2,3-二羧亚胺(4),测定了它们的生物活性。(4)中有5个化合物对水稻白叶枯病具有一定的保护作用。8个化合物对稻瘟病具有保护作用。     

吡嗪-2,3-二羧酸的合成新工艺

介绍了以二氨基马来腈和乙二醛为原料,经环化合成2,3-二氰基吡嗪,再经水解生成吡嗪-2,3-二羧酸的反应过程,全程反应条件温和,产品总收率高于65%。     

5,6-二甲基-2,3-吡嗪二甲酰胺-镍配合物的制备及其抗菌活性研究

以2,3-二甲基-5,6-二氰基吡嗪为原料,稀碱条件下不完全氧化得到配体5,6-二甲基-2,3-吡嗪二甲酰胺,再与醋酸镍在弱碱条件下合成5,6-二甲基-2,3-吡嗪二甲酰胺-镍配合物,通过红外光谱、紫外光谱、差热-热重分析对配合物进行表征。采用牛津杯法预试验及试管二倍稀释法研究配体5,6-二甲基-2,3-吡嗪二甲酰胺及其配合物的抗菌活性。结果表明5,6-二甲基-2,3-吡嗪二甲酰胺-镍配合物表现出一定的抑菌和杀菌作用,而配体没有明显的抑菌杀菌作用。     

吡啶并吡嗪/咪唑杂环化合物的合成研究

以2,3-二氨基吡啶或2,3,5,6-四氨基吡啶盐酸盐等为原料合成了吡啶并吡嗪、吡啶并咪唑及吡啶并二咪唑氮杂环衍生物。探讨了反应条件对产物收率的影响,初步确定了优化反应条件。对2,3-二甲基吡啶并吡嗪及2,3-二乙基吡啶并吡嗪的合成,氯化铵-甲醇体系具有明显的催化效果。使用4,5-二羟基咪唑烷-2-酮代替乙二醛与2,3-二氨基吡啶反应,可显著提高吡啶并吡嗪的合成收率;对于吡啶并咪唑和2-甲基吡啶并咪唑的合成,以2,3-二氨基吡啶与原甲酸三乙酯或原乙酸三甲酯为原料,在磷钼酸催化下反应,收率达50%以上;对于吡啶并[2,3-b:5,6-b']二咪唑和2,6-二甲基吡啶并[2,3-b:5,6-b']二咪唑的合成,分别以2,3,5,6-四氨基吡啶盐酸盐与原甲酸三乙酯和原乙酸三甲酯为原料在磷钼酸催化下反应,收率可达68.7%和66.5%。     

吡嗪并[1,10]菲咯啉类配体及其钯配合物的合成与表征

合成了两种吡嗪并[1,10]菲咯啉类配体-[2,3-f]吡嗪并[1,10]菲咯啉-2,3-二腈和[2,3-f]吡嗪并[1,10]菲咯啉-2,3-二羧酸,并将这两种配体与氯化钯反应,得到两种钯配合物.采用核磁共振谱和红外光谱表征了配体及其钯配合物的结构.     

新方法合成6-N-羟基吡咯并[3,4-b]吡嗪-5,7-二酮

以吡嗪-2,3-二羧酸为起始原料合成2,3-吡嗪二酸酐,在过量盐酸羟胺和无水碳酸钠溶液中反应得到3-羧基-2-吡嗪羟肟酸,再与氯化亚砜回流反应得到标题化合物,收率68%,其结构经IR、1HNMR和13CNMR确证。     

吡嗪酰胺的合成研究

研究了以邻苯二胺和乙二醛为原料,经过3步反应制备吡嗪酰胺的新路线.通过对各步反应条件的研究应用,得出第一步反应的最佳时间为90 min,此时收率达96.8%,第二步最佳回流时间为2 h,收率可达86.6%,第三步最佳反应物配比为m(尿素)∶m(吡嗪2,3-二羧酸)=1∶1.1,吡嗪-2,3-二羧酸与溶剂的最佳比例为1 g∶18 mL,产率可达40.2%.     

2—氯—3—烃基—5,6—二甲基吡嗪的合成及其烷氧基化和烷硫基化反应

５－烃基－２，３－二甲基吡嗪－１－Ｎ－氧化物与三氯氧磷在回流温度下反应制得６种－氯－３－烃基－５，６－二基吡嗪，产率７１－８２％。由２－氯－３－异丙基５，６－二甲基吡嗪与烷醇钠反应得４种相应的烷氧基取代吡嗪，产率２０．３－７０．３％。由固－液相转移催化２－氯－３－异丙基（或苄基）－５，６－二甲吡嗪与硫醇反应得４种相应的烷硫基取代吡嗪，产率４７．５－６８％。合成化合物的结构经元素分析和ＩＲ，＾１ＨＮ     

ZnFe_2O_4/ZnO气相法催化合成烷基吡嗪

改进的柠檬酸络合法制备了ZnFe2O4/ZnO催化剂,并用于乙二胺和2,3-丁二醇环化脱氢制备烷基吡嗪。用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)对催化剂进行了表征。考察了Zn/Fe摩尔比、反应温度、载气空速对2,3-丁二醇转化率和烷基吡嗪选择性的影响。结果表明,在n(Zn)∶n(Fe)=2∶1、反应温度380℃、原料液流速0.02 mL/min、载气空速1 440 h-1时,2,3-丁二醇的转化率为93.38%,烷基吡嗪的收率为85.47%,其中,2,3-二甲基吡嗪的收率为22.16%、2-甲基吡嗪的收率为63.31%。     

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.     

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。     

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.     

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.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。