丁二酸

Diethyl fumarate was synthesized with fumaric and alcohol as raw materials and sodium acid sulfate as catalyst.

富马酸二乙酯(又名反丁烯二酸二乙酯，Diethylfumarate，简称DEF)是一种用途广泛的有机合成中间体[1，2]。

A new solid acid based on heteropolyacid has been proved to be a useful catalyst for the synthesis of dibutyl maleate .

新催化剂在顺丁烯二酸二丁酯的合成反应中显示很好的活性和温和的反应条件。

From the reaction mechanism, which involved formation of benzodiazepinium ethoxycarbonylmethylate, the reaction mechanism, which involved formation of benzodiazepinium ethoxycarbonyl- methylate followed by cycloaddition reaction, was tentatively proposed.

通过研究反应过程中分离出的副产物反丁烯酸二乙酯III和4，5-二氢吡唑-3，4，5-三羧酸乙酯IV，初步提出了反应经过乙氧羰基甲基化苯并二氮杂卓翁中间体V再发生环加成反应的机制。

The coupling process of dehydrogenation of 1,4-butanediol and hydrogenation of dimethyl maleate over CuO/SiO2 catalysts to produce one important fine chemical γ-butyrolactone was carried out in a continuous fixed bed reactor under atmospheric pressure.

和传统的反应过程相比，耦合反应提高了顺丁烯二酸二甲酯加氢和1，4-丁二醇脱氢活性。

Firstly, 3-ethylthiobutanal was prepared from crotonaldehyde reacting with ethanehiol in triethylamine with high yield. Secondly, methyl acetoacetate was converted to 6-ethylthiohept-3-en-2-one by three steps via hydrolysis, condensation with 3-ethyltio-butanal and dehydration, then 6-ethylthiohept-3-en-2-one was cycloco ndensed with dimethyl malonate by Michael addition and Claisen condensation, followed by saponification and decarboxylation to give the intermediate of 5-(2-ethylthiopropyl)-cyclohexane-1,3-dione.

首先，以巴豆醛与乙硫醇为原料，在三乙胺的催化作用下高收率制得3-乙硫基丁醛；然后从乙酰乙酸甲酯出发，通过碱水解、与3-乙硫基丁醛缩合、脱水三步反应合成6-乙硫基-3-烯-2-庚酮，接着6-乙硫基-3-烯-2-庚酮与丙二酸二甲酯通过Michael加成和Claisen缩合成环，再通过皂化和脱羧反应生成中间体5-[2-丙基]-1，3-环己二酮；再与丙酸酐反应丙酰化，最后与0-3-氯-2-丙烯基羟胺肟化，得到目标化合物烯草酮。

ABSTRACT In this paper, by employing dicarboxylic acids with special conformation, i.

利用几个结构上有特点的二元羧酸，即2，6-吡啶二甲酸、三个异构体苯二甲酸，顺丁烯二酸和4，4'-联苯甲酸作为首要桥基配体，并结合使用含氮中性配。。。

Propargyl alcohol was protected by dihydrophran with the catalysis of PPTS ,and then reacted with Ethyl Mag bromide to prepare its corresponding Grignard reagent.

炔丙醇在 PPTS 催化下由二氢吡喃保护，与溴乙烷格氏试剂反应生成相应的格氏试剂，然后与氯甲酸甲酯反应得到羟基丁炔酸甲酯四氢吡喃醚，在 PPTS 催化下脱保护后进行甲磺酰化，由溴化钠进行溴取代后合成了4-溴-2-丁炔酸甲酯，总收率达53%。

In addition, the new phosphine-catalyzed cyclization reactions of dimethylacetylenedicarboxylate and methyl propiolate with N-tosylimines are also described.

发展了膦催化下丁炔二酸二甲酯和丙炔酸甲酯与贫电子亚胺的环化反应，这对2-炔酸酯的反应又是一个补充，进一步丰富了膦催化下贫电子炔烃的反应化学。

Segmented polyester polyurethaneurea based n 4, 4'-disphenylmethane diisocyanate, ethylene diamine and polybutylene adipate elastomers and their deuterated polymers were studied by means of IR spectroscopy.

用红外光谱法对基於4，4'-二苯基甲烷二异氰酸酯、乙二胺和聚己二酸丁二醇酯的嵌段聚酯型聚脲氨酯弹性体及其氘化產物进行了研究。

The degradation of 2, 4-dichiorophoxyacetic acid (2, 4-D) by ozonation combined with sonication (03/US) was investigated. Based on the authors' first paper about the synergistic effect of ozone and US, this paper presents intermediate products of 2, 4-D degradation. The main intermediates were 2, 4-dichiorophenol, benzopuinone, hydroquinone and organic acids, such as maleic acid and oxalic acid and soon.

利用臭氧超声波联合工艺对苯氧羧酸类除草剂2，4-D进行降解研究，在前文探讨臭氧超声波之间协同效应的基础上，确定其中间产物种类主要有2，4-二氯苯酚、苯醌、氢醌以及小分子酸如顺丁烯二酸、草酸、甲酸、乙酸等。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。