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A mild and convenient method for the synthesis of 4(3)-substituted 3(4)-nitro-1H-pyrroles and 3-substituted 4-methyl-2-tosyl-1H-pyrroles from nitroolefins and tosylmethyl isocyanide in ionic liquid 1-butyl-3- methylimidazolium bromide was developed.

本文以离子液体－溴化1-丁基-3-甲基咪唑为溶剂，采用对甲苯磺酰基甲基异腈与硝基烯反应生成4(3)-取代-3(4)-硝基-1-氢吡咯或3-取代-4-甲基-2-对甲苯磺酰基-1-氢吡咯。

Chromosome DNA was purified by isopycnic centrifugation in a CsCl-ethidium bromide.

氯化铯-溴化乙锭梯度离心法纯化DNA。

Three series of donor-acceptorπ-conjugated molecules 1, 2, and 3 have been designed and synthesized with a N, N-dimethylamino, Julolidine group (2,3,6,7-tetrahydro-1H, 5H-pyrido[3, 2, 1-ij]quinolinyl), or N, N-diphenylamino group as the donor moiety, a phenylvinyl or thienylvinyl unit as the bridge, and a bromide or aldehyde group as the acceptor moiety.

本文设计并合成了1、2、3三个系列的D-π-A型化合物(Donor-Acceptorπ-conjugated compounds)，在化合物分子中引入久洛尼啶基团(2，3，6，7-tetrahydro-1H，5H-pyrido-[3，2，1-ij]quinolinyl)，N，N-二甲基氨基，或N，N-二苯基氨基为供电子基团，以苯乙烯基或噻吩乙烯基为桥链，以溴原子或醛基为吸电子基团。

The intramolecular Reformatsky-type reaction of benzyl bromide and keto group is the key step.

其中关键步骤是苄溴与酮基的分子内Reformatsky型反应。

On the other hand, reaction of lactol derived from D-mannose and D-glucose with Grinard reagent of propargyl bromide also proceed both withanti stereoselectivity and with high anti-specificity.

链增长及目标分子中的碳碳双键是由一步Wittig反应和一步末端炔的烷基化再部分氢化而获得，双键构型-选择性可达到95％以上。

The results show that the optimal parameters of esterification are as follows: 4% of SO42-/ZrO2, molar ratio of methanol to litsea cubeba kernel oil 101, 68 ℃ of reaction temperature and 4 h of reaction time, the acid value decreases to 2.52 mg/g. Compared with the traditional acidic-catalyzed method, this method has the advantages of no acid proof equipment, easy to recycle catalyst and no acidic waste water emission. The optimal parameters of transesterification are as follows: 25 ℃ of reaction temperature, 0.5% of hexadecyl-trimethyl-ammonium bromide, 1% of NaOH, molar ratio of methanol to the oil 61 and 15 min of reaction time. The ester exchanging rate is 97.6%. This method adopts phase transfer catalyst and produces industry prospect, which has many advantages such as energy-saving and time-saving under room temperature.

研究结果表明，固体酸SO42-/ZrO2催化酯化反应的最佳条件为：油重4%的SO42-/ZrO2，醇油摩尔比为101，温度为68 ℃，反应时间为4 h，原油酸值降到2.52 mg/g；该法相对浓硫酸催化酯化法具有不需耐酸设备、催化剂易回收、无废水排放等优点；相转移催化酯交换反应的最佳条件为：温度为 25 ℃，0.5%的十六烷基三甲基溴化铵，油重1%的NaOH，醇油摩尔比为61，反应15 min，原油酯交换率达到97.6%；采用相转移催化技术，反应在常温下进行，大大减少了能耗，缩短了反应时间，具有的产业化前景。

Methods Activate groups A and C meningococcal polysaccharide with cyanogens bromide and prepare into MenAPS-ADH and MenCPS-ADH derivatives by reacting with 1, 6-adipic acid dihydrazine. Mix MenAPS-ADH and MenCPS-ADH derivatives with purified tetanus toxoid at a certain mass ratio, then add l-ethyl-3(3-dimethylaminopropyl)-carbodiimide to prepare bulks of MenAPS-TT and MenCPS-TT conjugates respectively. Mix the two bulks at a certain ratio, add stabilizer and lyophilize to prepare group A+C meningococcal polysaccharide conjugate vaccine.

A群和C群脑膜炎球菌多糖在溴化氰的活化下，以1，6己二酰肼作为连接子，与精制破伤风类毒素在碳二亚胺作用下结合，再按一定的比例将两者混合，制成A+C群脑膜炎球菌多糖结合疫苗原液，加保护剂冻干后，制成A+C群脑膜炎球菌多糖结合疫苗。

Silver nanoparticles with average particle size ranging from 2 to 131nm were manipulatively synthesized starting from silver nitrate using 10 kinds of different functional group-containing organic modifiers, such as polyvinylpyrrolidone, tween-80, sodium dodecyl sulfate, sodium polyacrylate, polyethylene glycol, D-sorbitol, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, polyvinyl alcohol, cetyltrimethylammonium bromide, at room temperature.

摘 要：选择10种含有不同官能团的有机物为表面修饰剂，如聚乙烯吡咯烷酮、吐温-80、十二烷基硫酸钠、聚丙烯酸钠、聚乙二醇、山梨醇、十二烷基磺酸钠、聚乙烯醇、十二烷基苯磺酸钠和十六烷基三甲基溴化铵等，在室温下进行了平均粒径在2～131nm范围内纳米银颗粒的控制合成研究。

For the first time, enantiomers of C2-symmetric 1,1 -spirobiindane-7,7'-diol were resolved with crude menthyl chloroformate by phase-transfer catalysis in the presence of tetrabutylammonium bromide. The reaction was carried out at 0℃-rt. The diastereomers of SPINOL bis-menthyl carbonate can be separated by simple crystallization using alcohol. The hydrolysis of the diastereomers was carried out via aqueous NaOH/EtOH solution.

首次通过相转移催化的方法对螺双二氢茚二酚进行了有效的拆分，用L--氯甲酸薄荷醇酯做拆分剂，以四丁基溴化铵为催化剂在0℃-室温下进行酯化反应生成非对映体衍生物，以乙醇作溶剂，通过重结晶的方法分离衍生物，在水-乙醇混合溶剂条件下，用强碱NaOH或KOH分别水解，制得相应的光学纯度大于99%ee的两个异构体SPINOL，其中总收率：--SPINOL，78.2%；--SPINOL，80.6%。

Nylon1010/montmorillonite nanocomposites were prepared by melt blending the polymer with MMT modified by metacresol, nylon66 salt, cetyl trimethyl ammonium bromide/MC, CTAB/NS respectively.

以间甲酚、尼龙66盐分别与十六烷基三甲基溴化铵共插层改性蒙脱土，制备了尼龙1010/蒙脱土纳米复合材料。

We are forbidden from giving money to these shoeless, skinny children, as this will perpetuate begging.

向光着脚，骨瘦如柴的孩子施舍是不可以的，因为要招来无休无止的乞讨。

It would be hard not to fall victim to some sharpeyed policeman.

要想不被某个目光锐利的警察抓到，谈何容易。