乙酸乙酯

Methods: Based on national standard, detected n-hexane, benzene, toluene, dimethylbenzene, ethyl acetate, butyl acetate and butanone in 450 factories.

根据中华人民共和国国家标准，对昆山市的450家接触正己烷、苯、甲苯、二甲苯、乙酸乙酯、乙酸丁酯、丁酮7种有机物的企业车间空气进行采样检测。

In our research on study chemical reaction of active methylene compounds and brom-acetophenone. Because of brom-acetophenone is compound that contain carbonyl and halogen ,which will take place electrophilic substitution and nucleophilic addition. When active methylene compounds are ethyl acetoacetate and β-diketone, controlling reaction condition, we have found that mono-substitution's production and di-substitution's. production is isolated; active methylene compounds are acetoacetanilide and acetoacetanilide derivate, pyrrolidin-2-one derivants were obtained by substitution and close-ring reaction .but there is no report about it.

本文是让活泼亚甲基类化合物与溴代苯乙酮发生化学反应，由于溴代苯乙酮是含有羰基的卤代烃结构，它可以发生亲电取代和亲核加成反应，当活泼亚甲基类化合物为乙酰乙酸乙酯和β-二酮时，控制反应条件可以发生单取代和双取代两种产物；当活泼亚甲基类化合物为乙酰乙酰芳胺类化合物来反应时，溴代苯乙酮中的羰基与氨基会发生分子内的关环反应生成吡咯烷-2-酮衍生物，这在以前的研究中是没有发现的。

Anhydrous ethanol ; glacial aletic acid ; anhydrous aluminium ; ethyl acetate ; catalyzed esterize

无水乙醇；冰乙酸；无水三氯化铝；乙酸乙酯；催化酯化

This thesis consists of four chapters:Chapter 1: Michael addition of chalcones with active methylene compounds such as diethyl malonate, ethyl acetoacetate and nitromethane catalyzed by potassium hydroxide in anhydrous ethanol results Michael adducts in 72-98% yield under ultrasound irradiation in 25-150min.

第一章：研究了超声辐射下，氢氧化钾催化的查耳酮与活泼亚甲基化合物如丙二酸二乙酯、乙酰乙酸乙酯和硝基甲烷的迈克尔反应。

A method for synthesizing sodium sulfoacetic is discussed,which sodium sulfoacetic is synthesized with sodium sulfite and ethyl monochloro acetate,with sodium sulfite and chloroacetic acid.

主要分别介绍用亚硫酸钠与氯乙酸乙酯合成磺酸乙酸钠和亚硫酸钠与氯乙酸合成磺酸乙酸钠。

The famciclovir was synthesized from purine by a series of steps by Acylation, Decarboxylation, Reduction ,and so on; Derivatives of these intermediates is described from the 6-chloro- 9H- purin-2-amine as raw materials in different conditions when the iodine and bromide were synthesized with the addition of two intermediate 6-bromo-9H-purin-2-amine and 6-iodo-9H-purin-2-amine; There is elaborated from the main part of a acetophenone, urineaminohydrochloride, phenylhydrazine, ethyl acetoacetate as raw material through a series of reactions to synthetic 3-phenyl-4-formylphenyl pyrazole and 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-aldehyde two pyrazole aldehyde, and then with 2-amino-6-chlorine-9-(2-methicillin-oxo-co-methyl-4-yl) purine reaction of the two new pyrazole purine Schiff bases.

本论文主是采用以鸟嘌呤为原料，经过一系列的酰基化，脱羧，还原等反应作用下最终得到了产物2-氨基-9-(4-乙酰氧基-3-乙酰氧基甲基丁基)嘌呤；其中的中间体衍生物主要是阐述从以2-氨基-6-氯鸟嘌呤为原料通过在不同的条件下进行溴代与碘代分别合成了另外两种中间体2-氨基-6-溴鸟嘌呤及2-氨基-6-碘鸟嘌呤；还有一部分主要是阐述从以苯乙酮，盐酸氨基脲，苯肼，乙酰乙酸乙酯为原料通过一系列的反应先合成3-苯基-4-醛基吡唑及5-氯-3-甲基-1-苯基-1H-吡唑-4-甲醛这两个吡唑醛，然后再与2-氨基-6-氯-9-(2-甲氧羰基丁酸甲酯-4-基)嘌呤反应得到了两个新型的吡唑嘌呤席夫碱

In view of the existence of the above shortcomings of traditional methods, using acetyl chloride instead of acetic acid as a raw material, do not use any catalyst, not heating, room temperature reaction synthesis of ethyl acetate.

鉴于传统方法存在以上缺点，采用乙酰氯代替乙酸作为原料，不使用任何催化剂，不加热，常温反应来合成乙酸乙酯。

Optically active ethyl-3-hydroxybutyrate,a useful chiral synthon,was prepared by stereoselective reduction of ethyl acetoacetate of the bread yeast in organic solvent.

利用面包酵母在非水相中不对称还原乙酰乙酸乙酯，制备了光学活性的手性化合物S-3-羟基丁酸乙酯。

The asymmetric reduction of prochiral P-oxo ester, aromatic ketone and aliphatic ketone to its corresponding chiral alcohol by yeast cells were studied respectively in this work when ethyl 4-chloro-3-oxobutyrate, acetophenone and 2-octanone were as the model substrates.

本文以4-氯乙酰乙酸乙酯、苯乙酮和2-辛酮分别为β-羰基酯、芳香酮和脂肪酮的模型底物，研究了利用活性酵母细胞催化这三类前手性酮不对称还原合成相应手性醇的反应特性。

Chloromethyl-4-hydroxyl-7-methyl-6,7-dihydrothiopheno pyrimidine,2-chloromethyl-4-methoxyl-7-methyl-6,7-dihydrothiopheno pyrimidine have been synthesized by the reaction of chloroacetamidine hydrochcoride 2-ethoxycarbonyl-4-methyl-tetrahydrothiophen-3-one and dimethyl sulphate in this paper.

以甲基丙烯酸乙酯、巯基乙酸乙酯和氯乙腈为原料高产率地合成了两种新型导电高分子单体化合物，并通过核磁氢谱、核磁碳谱、质谱等确定了它们的结构。

I urge any American living outside the country to get an early start checking his/her registration and receiving an absentee ballot, because it can take a while.

我奉劝身在国外的所有美国人早点着手核对登记表，并接收缺席选举人票，因为这得花点时间。

He is too young to join the army.

他太年轻了，还不能参军。