单磷酸阿糖腺苷的合成改进

改进单磷酸阿糖腺苷的合成工艺。将阿糖腺苷用三氯氧磷及磷酸三乙酯磷酸酯化,中间体水解后用三乙胺去除过量的盐酸,纯化后得单磷酸阿糖腺苷。单磷酸阿糖腺苷与对照品液相色谱保留时间一致,含量99.1%。本方法避免了柱色谱分离,易燃易爆及致癌化学品的使用,原料易得,工艺简单。总收率67%。     

9,10-二羟基环十六内酯的合成

紫胶桐酸是一种具有生物活性的长链羟基烷酸,可用于大环内酯的合成。以紫胶桐酸多羟基作为起始原料,利用高度稀释的合成策略,通过缩醛选择性保护邻二醇、直链前体内酯化环合及酸催化环缩醛脱保护三步反应制备得到了目标产物9,10-二羟基-环十六内酯,总收率为31%,所得产物经红外光谱(IR)、核磁共振氢谱和碳谱(1 H NMR和13C NMR)、电喷雾质谱(ESI-MS)表征得以证实。实验均在室温下进行,反应条件温和,简洁有效。     

一种高效制备硝基乙酸酯的方法

异唑为母核的化合物具有多种生物活性,如抗癌、抗菌、抗病毒、抗炎、镇痛等。硝基乙酸酯是制备异唑类化合物重要的原料,报道了一种新型的硝基乙酸酯类化合物的通用合成方法,共合成4个硝基乙酸酯类化合物。其中以3-羟基丙腈和2,2,6-三甲基-1,3-二氧(杂)芑-酮为原料,经亲核取代、缩合、氧化3步反应得到硝基乙酸-3-丙腈酯,其结构经IR、~1HNMR、~(13)CNMR和HR-MS确证,总产率为71.6%。新的合成方法具有操作简单、成本低廉、反应条件温和等优点,适合工业化生产。     

4-羟基香豆素生产技术

<正>一、项目简介4-羟基香豆素是目前香料市场中用量最大的合成香料之一,主要用于橡胶、塑料制品的增香剂以及香水、香皂和化妆品等的定香剂。同时,因其衍生物具有抗菌、抗艾滋病、抗肿瘤、抗氧化、抗凝血、降压、降糖等生理学性质,因此也是一类重要的精细化工中间体。目前合成4-羟基香豆素主要有以下几种方法:(1)以苯酚和丙二酸酯或丙二酸为原料合成法;     

1-(2-羟基乙基)-5-巯基四氮唑的合成研究

以乙醇胺等为原料,经缩合、保护、成环及脱保护反应合成了1-(2-羟基乙基)-5-巯基四氮唑.其中,用醋酐作为中间产物N-(2-羟基乙基)二硫代氨基甲酸甲酯中羟基的保护试剂;用浓盐酸为酸催化剂、丙酮为反应介质,通过控制反应的pH值脱除1-[(2-乙酰基)乙基]-5-巯基四氮唑中的乙酰基.该方法具有收率高(总收率72.0%)、成本低和操作简便等特点.     

卡维地洛的合成工艺研究进展

卡维地洛是一种治疗高血压病的第三代β受体阻滞剂,同时兼具有选择性?1受体阻滞剂作用,是一种大品种的高效抗高血压药物,但是在现有的制备方法中卡维地洛的收率较低。目前国内外对卡维地洛的合成报道较多,但是对卡维地洛制备工艺路线的综述鲜有报道。根据起始原料的不同可以分为多种合成路线,本文着重分析了氮上含保护基团的反应和氮上不含保护基团的两种反应类型,保护氮的方式可通过分子间亲核取代反应引入苄基等保护基团和通过分子内反应形成环酰胺结构保护氮。通过分析及优化,指出以中间体4-羟基咔唑作为起始原料的反应,可以有效避免多种副产物的产生,从而能够显著提高卡维地洛的收率。     

N-羟基邻苯二甲酰亚胺的简便合成

N-羟基邻苯二甲酰亚胺(NHPI)是一种重要的化工原料;文章以盐酸羟胺、甲醇钠和邻苯二甲酸酐为原料,以甲醇为溶剂,合成了NHPI;该法合成和分离步骤简单,合成产率高(84%),产物纯度高(98.5%);简要讨论了合成反应的原理,分析了影响合成和产物分离提纯的一些因素。     

固—液相转移催化法合成羟基乙酸酯

羟基乙酸酯是合成具有抗癌活性的异三尖杉酯碱及其类似物和润滑油添加剂的重要中间体。最近,李绍白等报道了羟基乙酸酯的新合成法。我们参照此文献,以羟基乙酸钠和卤代烃为原料,用聚乙二醇(PEG)作固-液相转移催化剂(PTC),以 N,N-二甲基甲酰胺(DMF)作溶剂,在适宜的反应温度下,较快且较高产率地合成了几种羟基乙酸酯。基本反应式为:     

新法合成α溴代酸酯

α-溴代酸酯对皮肤、粘膜具有强烈的刺激性和腐蚀性,因而在军事上用于制造催泪弹、毒气弹。它还具有抗血吸虫、驱钩虫、杀打线虫等作用。这类化合物在锌粉存在下与醛或酮发生Reformatsky反应,是合成β-羟基酸酯的重要原料。我们以一种新型酯化反应催化剂     

4-羟基-3,5-二碘苯甲酸乙酯的合成工艺研究

4-羟基-3,5-二碘苯甲酸乙酯是一种重要的医药化工中间体,广泛应用于药物和生物活性材料的制备。本文以4-羟基苯甲酸乙酯为原料,经一步碘代反应得到目标化合物。该合成方法具有操作简单、后处理简便的优势。本文对合成反应中反应介质、碘化剂的选取及碘化剂用量、反应温度等反应条件进行了优化,产品收率为93.2%,符合工业生产的要求。该方法为4-羟基-3,5-二碘苯甲酸乙酯的合成提供了有效的合成路线,也为此类化合物的研究奠定了基础。     

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。