酰化

Treatment of pterin (2-amino-4-hydroxy-pteridine) derivatives with N,N-dimethylformamide dimethylacetal [1,(CH 3) 2NCH(OCH 3) 2] usually gave corresponding N 2-(N,N-dimethylaminomethylene)- pterin derivatives in polar solvents.

用N ，N 二甲基甲酰胺缩二甲醇 [(CH3 ) 2 NCH(OCH3 ) 2 ，1]和蝶呤(2 氨基 4 羟基蝶啶)衍生物在极性有机溶剂中反应一般得到脒化产物：N2 (N ，N 二甲基氨基亚甲基)-蝶呤衍生物。

Moreover, the protein-free spreading-free spreading technique, involvingbenzyldimethyl-alkyammonium bromide and the denaturing agent formamide, wasestablished. With very low DNA concentration, the fully extended DNA samples for linearDNA can be prepared.

采用Sephadex色谱柱分离，保温稀释的DNA溶液，不仅可除去DNA链上吸附的盐，而且可使盘绕一起的DNA链部分展开；在此基础上，通过采用苯二甲基辛基溴化胺－甲酰胺微量展层技术，可使纳克级DNA完全展开到云母基底上。

Aminophenyl ketones can be synthesized from different anilines and nitriles in the presence of boron trichloride, or from anilines by Friedel-Crafts reaction.

邻氨基芳香酮则可以由不同取代的苯胺与不同的腈在三氯化硼的作用下生成，或者通过傅克酰基化反应得到。

Neoformans via the tail vein）, CTX group and controls. The expres- sion of BDNF and bFGF was detected by immunohistochemical technique. Results: Lots of C.

48只C57BL／6雌性小鼠随机分为对照组、环磷酰胺组和试验组，免疫组化法检测大脑皮质BDNF和bFGF的表达。

The key steps involve the utility of Evans oxazolidinone-mediated syn-aldol condensations to establish the C-9 configuration and the macrolides ring formation by intramolecular acylation.

此路线的关键步骤包括Evans模板控制的Aldol反应以及分子内苯环上的酰基化反应。

Onset decomposition temperature of the polyimide was at 508 ℃ under nitrogen atmosphere, and its glass-transition temperature was at 288 ℃. The polyimide film had strengths at break at 91 MPa, elongations to break of 10%～15%, and initial moduli at 1.7 GPa.

此外该聚醚酰亚胺还表现出良好的热性能和机械性能：玻璃化转变温度在288 ℃，氮气中起始分解温度在508 ℃；该聚合物薄膜的拉伸强度为91 MPa，断裂伸长率在10%～15%，起始模量为1.7 GPa。

Optimum conditions are as follows: DMF is used as solvent, compound quaternary ammonium salt as catalyst, n(p-nitrochloro benzene):n=1: 1.2, m:m(p-nitrochloro benzene)=4%, m:m(p-nitrochloro benzene)1:1, and reacted under 155~160℃ for 18 h; reduction reaction is carried out in methanol with Raney nickel, which is used as catalyst; the raw product is added an antioxidant, and distilled simply under reduced pressure to obtain 4-fluoroaniline with excellence quality, purity is over 99.5%, total yield is 89.3%.

实验结果表明，氟化反应的最佳条件为：二甲基甲酰胺为溶剂、复合季铵盐为催化剂，n：n=1：1.2，m（催化剂：m=4%，m：m=1：1，于155~160℃下反应18h；还原反应在甲醇中进行，以阮内镍为催化剂；粗产品加入抗氧剂，减压条件下简单蒸馏得高品位的对氟苯胺。

The high selective resolution system was constructed with the mixture of isooctane with octanol acting as reaction medium and octanol as acyl acceptor.

建立了异辛烷／正辛醇的混合溶剂为反应介质、正辛醇为酰基受体的高度选择性的酯化拆分体系，并利用水合盐缓冲技术使反应过程中水活度保持恒定。

General F-C acylization reaction can not achieve our purpose for γ-oxoacyliation to heliotropin.

常规的付克酰基化反应难以合成上述目标中间物。

Then dendrimer-like polyamidoamine on the silica gel surface was prepared using Micheal addition of the amino and methyl acrylate,and ester-exchange of ethylene diamine and the ester group.

用硅烷偶联剂对硅胶表面进行氨基功能化，利用氨基与丙烯酸甲酯发生的Michael加成反应和乙二胺与酯进行的交换反应在硅胶表面合成了聚酰胺-胺树状大分子。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。