查询词典 acid anhydride

The results show high selectivity when the temperature is controlled at 50 CC , and the nitrated reaction time is 90 mm, toluene is nitrated by using 95% nitric acid as nitrating reagent at the presence of acetic anhydride, 1.0g silicotungstic acid catalyst is calcinated at 300℃ for 1.5h. The o/p (ratio of ortho to paro isomer of toluene nitration) ratio is 0.89 in product distribution of toluene nitration, lower than 1.67 using sulfonitric acid as catalyst. The yield of products is 91.6%.

结果表明，在醋酐存在条件下，以CCl4为溶剂，以质量分数为95%的硝酸为硝化剂，反应温度控制在50℃，反应60 min， 1.0g经300℃焙烧1.5h后的硅钨酸催化剂，对甲苯表现出强的区城选择性，甲苯硝化产物o/p值（甲苯硝化产物邻位和对位异构体的质量比）达0.89，较硝硫混酸的1.67显著降低，产物收率达到91.6%。

Piperidinecarboxylic acid is used as the raw material and acetic acid as the acylating agent, followed by the addition of some acetic anhydride in the later stage to get an important organic intermediate n-acetylpiperidine-4 carboxylic acid in the yield of 92%. Toluene is used as the solvent instead of sulfinyl chloride in the acyl chlorination to produce n-acetylpiperidine-4-carbonyl chloride with the yield of 97%.

以4-哌啶甲酸为原料、醋酸为酰化剂，后期加入少量醋酸酐反应得到中间体N-乙酰基哌啶－4-甲酸，收率92%；在甲苯溶剂中进行酰氯化得目标产物N-乙酰基哌啶－4-甲酰氯，收率97%。

This year the company operating the various organic chemical raw materials, varieties are: methanol, ethanol, ethylene glycol, butanol, isobutanol, isopropanol, glacial acetic acid, vinyl acetate, B lipid, Ding acetic acid lipid, styrene, toluene, phthalic anhydride, xylene, acetone, butanone, cyclohexanone, DMF, sulphuric acid, methyl isobutyl ketone, glycol Dingmi, three toluene, 2 Xin fat, melamine.

本公司常年经营各种有机化工原料，品种有：甲醇、乙醇、乙二醇、正丁醇、异丁醇、异丙醇、冰醋酸、醋酸乙烯、醋酸乙脂、醋酸丁脂、苯乙烯、甲苯、苯酐、二甲苯、丙酮、丁酮、环己酮、DMF、硫酸、甲基异丁基酮、乙二醇丁醚、三甲苯、二辛脂、三聚氰胺。

Iminodiacetic acid and aspartic acid reacting with t-butyloxycarbonyl anhydride in the basic solvent system of 1,4-dioxane-water gave better yields than those from conventional t-BuOH/H 2O system method,while glutamic acid in both solvent systems of 1,4-dioxane-water and tetrahydrofuran-water also gave better yield.

其中Boc酐法反应条件温和，操作简便，试剂易得且经济，是实验室制备Boc保护的氨基酸的常用方法。常规Boc酐法多采用叔丁醇水和四氢呋喃水的溶剂体系。我们用常规Boc酐法制备Boc 亚氨基二乙酸时，多次重复，收率总是低于 5 0 %，对天冬氨酸和谷氨酸进行Boc化时也有类似情况。

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。

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。

The kinetics on the hydrogenation of maleic anhydride to succinic anhydride has been studied.

在反应条件考察的基础上，对顺酐均相加氢生成琥珀酸酐的反应动力学进行了研究。

The production technology and market for maleic anhydride are reviewed, and some advice about development of China's maleic anhydride industry is put forward.

分析了顺酐生产技术进展及国内外市场，提出了我国顺酐发展的建议。

Market respect: Middleman near future holds goods to wait for more go up, shipment is not much, the city after be opposite holds hopeful state of mind, the stock up before partial businessman section did not go out, section hind is purchased somewhat again, money is managed in the hand more, overall for, at present suitable anhydride market has certain supply of goods, but manufacturer and middleman cherish goods sell, market of predicting later period is small go tall to come after the psychological price of manufacturer and middleman, market supply of goods is met somewhat grow in quantity, short-term inside the space that arranges anhydride to still small go tall.

市场方面：中间商近期多持货待涨，出货不多，对后市持乐观心态，部分商家节前备货没出，节后又有所采购，手中持货较多，总体来说，目前偏苯三酸酐市场有一定货源，但厂家及中间商惜货出售，预计后期市场小幅走高至厂家和中间商的心理价位之后，市场货源会有所增多，短期内偏苯三酸酐仍有小幅走高的空间。

This week crude oil rises considerably, break through 70 dollars / bucket, carry further went up the businessman's state of mind, reach cooking benzene in upriver crude benzole at the same time prop up below, the businessman accumulates ecstasy to watch to arranging the city after anhydride, predicting near future arranges anhydride prices to will still continue to go up, but as a result of downstream demand low fan, fear pulling go up the space is limited.

本周原油大幅上涨，突破70美元/桶，进一步提涨了商家的心态，同时在上游粗苯及焦化苯的支撑下，商家对偏苯三酸酐后市积极乐观，预计近期偏苯三酸酐行情仍将继续上行，但由于下游需求的低迷，恐拉涨空间有限。

The circulation, consumption and reproduction of the trilogy have not only testified to its historical significance and literariness, but also invested it with new meanings.

该三部曲的流通、消费与再生产不仅验证了其历史意义及文学性，而切还赋予它以新的意义。

If he thought that he could buy me off, he would be wrong.

如果他认为他可以收买我，那他就大错特错了。