查询词典 acetic anhydride

This paper summarized preparation technology and the production application at home and abroad for acetic anhydride ,and suggestions of production and development for acetic anhydride in our country was put forward.

综述了醋酐的生产技术及国内外的生产应用状况，并对国内外醋酐的生产发展提出建议。

Citric acid anhydride was synthesized by citric acid and acetic anhydride with acetic acid as solvent.

以柠檬酸和乙酸酐为原料，乙酸为溶剂合成柠檬酸酐。

Acetic anhydride was a very important chemical raw material, which was widely used in many fields of the national economy. There were more preparation methods for acetic anhydride, however, using coal into an important chemical materials was the states key research project.

醋酸酐是非常重要的化工原料，广泛的运用于国民经济多个领域，制备方法比较多，但利用煤炭转化为重要的化工原料是国家重点研究项目。

All compounds are synthesized starting from the acylation reaction of gallic acid with L-glutamine to form the basic scaffold, followed by the cyclic reaction in acetic anhydride and the key intermediate cyclic anhydride (compound 4) was obtained. The intermediate compound is condensed with different amino acids or primary amines, and produces the target compounds.

本研究以L－谷氨酸为基本骨架，与甲醚化保护的没食子酸缩合后，经过酰化、环合反应得到关键中间体环状酸酐（化合物4），再经胺解反应合成目标化合物，其化学结构经过红外光谱、电喷雾质谱和核磁共振谱（氢谱、碳谱、碳氢异核多键相关谱）确证。

Amino to acetyl phenol, in have technology of two kinds of production domestic and internationally, acetic anhydride craft of the United States, acyl changes temperature to have 75 ℃ only, acyl changes mother liquor not apply mechanically, deputy reaction is little, of production thick tasting is kind of white almost, purificatory craft is very simple, activated carbon dosage only 2~3%, the Kun that its product does not have glow material almost in different third alcohol inferior the sealed impurity of amine impurity and minim, settleclear lightness it may not be a bad idea, the product quality that acetic anhydride craft produces is good, but close rate low, cost is high.

对乙酰氨基酚，在国内外有两种生产工艺，美国的醋酐工艺，酰化温度只有75℃，酰化母液不套用，副反应少，生产的粗品几乎是类白色，精制工艺就非常简单，活性炭用量仅2~3%，其产品在异丙醇中几乎无红光物质的醌亚胺杂质及微量的未知杂质，澄明度也好，醋酐工艺生产的产品质量好，但收率低、成本高。

Kinetics of photo-chlorination of acetic acid to form monochloroacetic acid ;2. The mechanism for chlorinate acetic acid to monochloroacetic acid by using acetic anhydride or sulfur as catalysts respectively was studied.

通过对硫磺和乙酐催化氯化制备氯乙酸反应机理的分析研究，采用硫磺及乙酐复合催化剂，并且对氯化温度、氯化气氛、尾气回收等进行了过程优化，实现了乙酸氯化反应工艺条件的重大突破，使得氯乙酸的收率达到92。

The yield of coumarin could be reached up to 86.6% with lower consumption of acetic anhydride in case the total molar ratio of acetic anhydride to salicylaldehyde=1 9∶1 and the reaction was...

水杨醛与乙酸酐的总摩尔比为 1∶1.9，反应近终点时在( 2 14± 2 )℃保温反应 0 。5h，香豆素收率达 86.6%。

The yield of coumarin could be reached up to 86.6% with lower consumption of acetic anhydride in case the total molar ratio of acetic anhydride to salicylaldehyde=1.9∶1 and the reaction was kept 0.5 h at 212～216 ℃ when the reaction was close to the end.

水杨醛与乙酸酐的总摩尔比为1∶1 。9，反应近终点时在(214±2)℃保温反应0.5 h，香豆素收率达86.6%。

Citric acid anhydride was synthesized by citric acid and acetic anhydride with acetic acid as solvent.

柠檬酸酐是由柠檬酸两个羧基间脱水形成的，具有吸水性和酰化能力，是合成农药、医药、食品、饮料、清洁剂、化妆品和树脂的一种重要的中间体[1-2]。

The experimental results show that in the presence of acetic anhydride, the L-tyrosine can be completely racemized and converted into DL-tyrosine both in NaOH aqueous solution and in acetic acid solvent, and moreover, in the presence of acetic anhydride

今讨论了在碱性水溶液中，L-酪氨酸、乙酸酐和NaOH三者摩尔比例对消旋过程的影响和在纯乙酸溶剂中，乙酸用量和L-酪氨酸与乙酸酐的摩尔比例与消旋温度对消旋过程的影响。结果表明在乙酸酐的作用下，L-酪氨酸在纯乙酸溶剂中的消旋具有消旋速度快，DL-酪氨酸收率高的优点。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了