硼氢化钠/氯化钙新法还原乙酰基二茂铁合成1-二茂铁基乙醇

采用硼氢化钠/氯化钙还原体系将乙酰基二茂铁还原为1-二茂铁基乙醇。探讨了硼氢化钠、氯化钙的用量及反应时间对还原产物收率的影响,得到了乙酰基二茂铁还原的优化条件:投料比n(FcCOCH3)∶n(NaBH4)∶n(CaCl2)=1∶3∶2,以甲醇为溶剂,在碱性条件下回流1.5 h。在此条件下,1-二茂铁基乙醇的收率达87.5%。利用IR、1H NMR和元素分析对产物进行了结构确证。     

6-氮杂-螺[3,4]辛烷盐酸盐的合成

以环丁酮(1)为起始原料,与磷酰乙酸三乙酯经Witting-Horner-Emmons反应得2-环丁烯基乙酸甲酯(2),然后与硝基甲烷经迈克尔加成得2-(1-硝基甲基)环丁基乙酸甲酯(3),再经氢化还原、分子内胺解得6-氮杂-螺[3,4]辛烷-7-酮(4),最后经氢化铝锂还原、酸化等5步反应得到目标化合物6-氮杂-螺[3,4]辛烷盐酸盐,总收率为27%。其结构经1H NMR和MS进行确证。     

合成乙烯基二茂铁的简易方法

乙烯基二茂铁的合成方法,以往是将二茂铁在磷酸等催化剂作用下与乙酸酐或乙酞氯反应合成单乙酰基二茂铁,分离后用氢化锂铝或硼氢化钠还原成a-二茂铁基乙醇,再经脱水制成乙烯基二茂铁。此方法按原始原料计算乙烯基二茂铁的产率很低。本文提出依据二茂铁在低温浓硫酸溶液中,与醛反应生成a-二茂铁正碳离子的反应机理,不经分离即可脱水,制得乙烯基二茂铁。该方法可使乙烯基二茂铁的产率大大提高。其反应式如下:     

2-(4-哌啶基)乙醇的合成工艺的研究

2-(4-哌啶基)乙醇是治疗精神分裂药物哌泊噻嗪的一个关键中间体。本文以苄基哌啶酮为起始原料,经Wittig反应,四氢铝锂低温还原、兰尼镍还原脱苄基反应得到目标化合物。并考察了四氢铝锂还原反应还原剂的用量、反应温度,兰尼镍还原反应还原剂的用量、反应压强、反应温度对反应收率的影响。优化后3步反应总收率可达55.7%,且反应条件温和,后处理简便,产品经ESI-MS和1HNMR确证结构。     

S-1-(4-乙氧基苄基)-3-氮杂戊烷-1,5-二胺的合成

以N-叔丁氧羰基-L-酪氨酸甲醋酯原料,经乙基化反应,再与无水乙二胺进行酯交换反应,然后用三氟乙酸脱除氨基保护基,最后用氢化铝锂还原酰胺基制得标题化合物.该工艺避免了高压、氢气、乙硼烷等对设备、安全性要求高的条件,反应温和可控,反应周期短,安全性高,收率高.     

S-1-(乙氧基苄基)-氮杂戊烷-1,5-二胺的合成

以N-叔丁氧羰基-L-酪氨酸甲醋酯原料,经乙基化反应,再与无水乙二胺进行酯交换反应,然后用三氟乙酸脱除氨基保护基,最后用氢化铝锂还原酰胺基制得标题化合物.该工艺避免了高压、氢气、乙硼烷等对设备、安全性要求高的条件,反应温和可控,反应周期短,安全性高,收率高.     

2,2-二氟乙醇的合成

在四氢呋喃为溶剂的情况下,我们采用四氢铝锂还原二氟乙酸苯甲酯生成二氟乙醇。并探讨了反应温度、反应时间和四氢铝锂等因素对反应的影响。结果表明:在温度0℃条件下,n(LiAlH_4)∶n(CF_2HCOOCH_2C_6H_5)=0.7,V(CF_2HCOOCH_2C_6H_5)∶V(THF)=1∶4时,二氟乙醇的收率可以达到99.26%。     

三叔丁氧基氢化铝锂的新型制备方法

本文采用了价廉、易得的金属钠和氯化锂,代替价格昂贵的金属锂,成功制得了氢化锂和氯化物混合物,以及未反应完的氯化锂。以此为原料制得了氢化铝锂,收率在百分之九十以上,并与叔丁醇反应,制得了纯度≥98%的三叔丁氧基氢化铝锂,收率在95%以上。     

反，反-2，4-己二烯醛醋酸酯的合成

以山梨酸为起始原料,经酯化、选择还原和酯化合成反,反-2,4-己二烯醛醋酸酯。山梨酸甲酯的还原反应以氢化铝锂为还原剂,加入无水三氯化铝减弱还原活性,保护共轭双键,收率约79％,高于文献报道。本文方法操作简单易行,对溶剂和设备无特殊要求。     

(2-氘)丙-2-胺盐酸盐的合成研究

以廉价易得的丙酮肟为原料,通过氘化铝锂还原,与氯化氢二氧六环溶液成盐得到目标化合物(2-氘)丙-2-胺盐酸盐。其结构经~1 HNMR和ESI-MS确证。最佳反应条件为:n(丙酮肟)∶n(氘化铝锂)=2∶1,反应溶剂为四氢呋喃,在70℃下反应3h,产品收率为52%。     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。