查询词典 ethyl acetoacetate

Supported 12-Phosphotungstic Acid and Its Salts as Catalysts for the Synthesis of Fructone and Fructone-B;2. Their catalytic activities were measured by synthesis of fructone-B from ethyl acetoacetate and 1,2-propanediol.

制备了一系列以脱铝超稳Y沸石为载体的磷钨酸及其铯盐催化剂，考察了催化剂在以乙酰乙酸乙酯和1，2-丙二醇为原料催化合成草莓酯反应过程中的性能。

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。

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

Four substances including 2-methyl ethyl acetoacetate and barley straw extract distilled from bulrush as well as cetyl trimethyl ammonium bromide and isothiazo lintone were used for the comparison experiment in inhibiting the growth of Microcystis aeruginosa in various phases. Result showed that inputting chemicals in the lag phase has better effect than in the log phase, and adding in lag phase can effectively inhibit the algae growth. Although feeding allelopathic substance at log phase can lead to certain restraining effect, it cannot result in the effective inhibition of algae growth, which can be well achieved by feeding CTAB and isothiazo lintone below 10mgl/L during log phase.

研究用从芦苇中提取的2-甲基乙酰乙酸乙酯和大麦秸浸出液两种化感物质以及十六烷基溴化钱和异噻唑啉酮等四种药剂对不同生长期的铜绿微囊藻进行了对比抑制试验，结果显示在铜绿微囊藻生长的迟缓期投加试验药剂效果比在对数期投加效果都好，在迟缓期投加四种药剂，都有很好的抑藻效果；在铜绿微囊藻生长的对数期投加化感物质，虽然有一定的抑藻率，但效果较差，而在藻对数期投加10mg/L以下的CTAB和异噻唑啉酮能达到很好的水华抑制效果。

Could keep above 95% in the fixed beds. In order to achieve high stereo-selectivity with yeast, ethyl acetoacetate was used as the model substrate,and a novel approach was proposed to selectively inhibit R-enzymes in yeast before reaction.

以乙酰乙酸乙酯为模型底物，以丙烯酸、乙醚、二甲基亚砜、丙烯酰胺、正己烷等有机溶剂选择性地抑制酵母中R型酶，提高反应立体选择性。

Bromo-5-formyl -3-methylpyrrole is an important intermediate of tolyporohin. On the base of introducing the present research and development of tolypo- rohin and pyrroles ramification at home and abroad, an emphasis was made on synthesis of 2-Bromo-5-formyl -3-methylpyrrole and the technical conditions of all steps, which was described as follows. Diethyl 3,5-dimethylpyrrole-2,4-dicarboxylate was made by nitrification, reduction and cycle of ethyl acetoacetate.

由于2-溴-5-甲酰基-3-甲基吡咯是合成托尼卟吩的重要中间体，本文在阐述了当前托尼卟吩及吡咯衍生物的国内外研究和开发的基础上，重点研究了2-溴-5-甲酰基-3-甲基吡咯的合成，并对各步反应进行了工艺研究，具体合成步骤如下：本文通过对乙酰乙酸乙酯的亚硝化、还原、成环，反应生成吡咯单环衍生物2，4-二乙氧羰基-3，5-二甲基吡咯。

7-Hydroxy-4-methylcoumarin was synthesized from ethyl acetoacetate and m-dihydroxybenzene by the Pechmann condensation using phenyl sulfonic acid as catalyst under solvent-free conditions.

摘 要：以苯磺酸作催化剂，乙酰乙酸乙酯和间苯二酚为原料，通过Pechmann缩合反应合成7-羟基-4-甲基香豆素。

Synthesis 3,5-dihydroxytoluene by ethyl acetoacetate and diketene as material(yield 6%),by 3-methyl-4-chlorophenol and KOH as material(yield 30-40%)respectively,It was solved for product separation and purify.

分别以乙酰乙酸乙酯与双乙烯酮为原料(收率6%)、3-甲基-4-氯苯酚与氢氧化钾为原料(收率30-40%)合成了3，5-二羟基甲苯，解决了产品分离纯化问题。3-甲基-4-氯苯酚路线进行了中试，中试收率为20%。

Dihydropyrimidin-2 (1H)-ones were synthesized by condensation of aromatic or aliphatic aldehydes, urea and ethyl acetoacetate or acetylacetone one-pot three-component Biginelli condensation in the presence of room temperature ionic liquids as catalysts under solvent-free conditions.

5利用室温离子液体作催化剂，芳香或脂肪醛、尿素和乙酰乙酸乙酯或乙酰丙酮三组分缩合制备3，4-二氢嘧啶-2-酮衍生物。

Base played a crucial role in this reaction: in the Pd2/L1 catalyzed α-arylation of ethy malonate, K3PO4 is the base of choice; in the α-arylation of ethyl acetoacetate, K2CO3 is the most effectiv base.

在这类催化反应中，碱的选择具有重要的影响：以K3PO4为碱，Pd2/L1催化体系在丙二酸二乙酯的α-芳基化中，富电子溴代芳烃显示较好的活性；Pd2/L1催化的乙酰乙酸乙酯α-芳基化时，以K2CO3为碱，催化体系显示较好的活性，这个催化体系可控制反应得到α-芳基乙酰乙酸乙酯，而不是脱乙酰基的产物。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。