查询词典 methyl group

Thus,Route 1 was not able to continue.In Route 2,the methyl groups of 6 could be developed from cyanos by different pathways individually(Scheme 5).In this thesis,we have completed the protection of one ketone group of 11,and further synthesis is currently under investigation.

在类似物的合成研究过程中，我们还取得了如下成果：(1)通过对中间体8的合成，发展了一种四氧化三铅现场氧化酚成醌，并进一步催化醌参与(来源：Af6BC论文网www.abclunwen.com)的Diels-Alder反应一锅化的方法。

In the coupling reaction of 4 with 2-methyl-1-buten-3-yne the four- membered ring ligand is transferred to enyne to give the substituted eta3-butadienyl complex 5 containing the cyclobutenonyl group.

在4与2-甲基-3-炔-1-丁烯进行偶合反应后，四环结构仍然稳固存在，并转移到烯缺上形成一个含有四环结构的错合物5。

In order to obtain the thermodynamic data of the synthesis of ethyl methyl carbonate from dimethyl carbonate and diethyl carbonate, the standard molar enthalpies of formation, Gibbs free energy and molar heat capacity under constant pressure are calculated by the method of Benson group contributions.

为了得到碳酸二甲酯和碳酸二乙酯酯交换合成碳酸甲乙酯反应的热力学数据，用Benson基团贡献法计算了相关物质的标准摩尔生成焓、吉布斯自由能和摩尔定压热容。

At the same time, the enthalpy change of 212 kJ/mol for Tempo trapping methyl radical, namely O-〓 bond dissociation energy has been also obtained. This value is close to that of nitrous acid ester and far less than that of nitric acid ester. It is probably due to the relatively strong electron withdrawing capability of nitryl group.

同时我们还测得了甲基自由基与Tempo的反应的焓变，即O—〓键离解能为212 kJ／mol，它接近于亚硝酸甲酯中C—O键的离解能，而小于硝酸甲酯中的键离解能，这可能和硝酸根的吸电子能力较大有关。

According to the H NMRstudy, it was found that the protons on the cyclopentadienyl ring of 〓 were not splitted, but when one proton on the cyclopentadienylring was substituted by methyl, that is in〓 complexes, thefour protons on the ring were splitted into four groups,the 〓 between the onesignal and the others is large, the total splitting is over 2ppm. The splittings werealso affected by the halides linked with the titanium, they increase according to theorder of CI, Br, I. By the study of the 〓 Sn NMR, it is found that the chemicalshifts of 〓 are present in low field. It is assume that the large space strain causesthe angles of the tin linked with ligands deviate from the normal tetrahedral anglesresults low field shift for 〓Sn. And by MS study,there were no molecular ions for 〓 complexes in the spectra. However, for 〓 when X=CI,Br,NCO and Ar is tolyl or phenyl group,there were molecular ions,but theirabundances were very small,and no that for the iodide was found.

钛上的卤素对茂环氢的裂分也有影响，依〓，Br，I顺序，卤素对茂环氢的裂分依次加大；通过对〓的研究发现，以上这些化合物〓的化学位移都出现在低场，认为大的空间张力造成的锡的键角偏离正常的锡的四面体键角是造成〓化学位移出现在低场的原因；对这些化合物质谱的研究发现，〓系列化合物得不到分子离子峰，而〓系列的化合物，当X=〓，NCO和苯环上不带取代基或只带甲基时，则出现分子离子峰，但丰度很低，而相应的碘化物和其它化合物则没出现分子离子峰。

composite latex ; methyl acrylic acid ; particle size ; carboxylic group distribution ; alkalic thickening

本文研究了复合乳化剂浓度、聚合方法对 St/BA/MAA复合胶乳的粒子大小、羧基分布及碱增稠性的影响。1 实验部分1

The general formulas of these compounds are as follows:The strobilurin derivatives were synthesized from substitutedβ-keto esters (2) as starting material which were prepared from substituted ketones (1) and dimethyl carbonate. The ester (2) and methyl hydrazine or substituted amidine were dissolved in methanol and the mixture was heated to reflux to obtain the substituted 5-hydroxy-1H-pyrazole (3) or 4-hydroxy-pyrimidine (4). The title compounds were prepared by reacting the intermediates (3 and 4) with substituted halomethylphenyls which contain four active group under basic conditions.

本论文所合成的strobilurin化合物均是以β-酮酸酯类化合物(2)为起始原料合成的，该中间体(2)是由酮类化合物(1)与碳酸二甲酯在碱性条件下反应生成的，中间体(2)与甲基肼或取代脒类化合物在甲醇中回流制得取代的1H-5-羟基吡唑(3)或4-羟基嘧啶(4)，中间体(3和4)再与包含四种活性基的苄卤中间体在碱性条件下制得目标化合物。

The genera formulas of these compounds are as follows:The strobilurin derivatives were synthesized from substitutedβ-keto esters (2) as starting material which were prepared from substituted ketones (1) and dimethyl carbonate. The ester (2) and methyl hydrazine or substituted amidine were dissolved in methanol and the mixture was heated to reflux to obtain the substituted 5-hydroxy-1H-pyrazole (3) or 4-hydroxy-pyrimidine (4). The title compounds were prepared by reacting the intermediates (3 and 4) with substituted halomethylphenyls which contain four active group under basic conditions.

本论文所合成的strobilurin化合物均是以β-酮酸酯类化合物(2)为起始原料合成的，该中间体(2)是由酮类化合物(1)与碳酸二甲酯在碱性条件下反应生成的，中间体(2)与甲基肼或取代脒类化合物在甲醇中回流制得取代的1H-5-羟基吡唑(3)或4-羟基嘧啶(4)，中间体(3和4)再与包含四种活性基的苄卤中间体在碱性条件下制得目标化合物。

The 6- cyano-1, 1 (1, 3- dioxypropylidene)-7-(carbomethoxyl group- methyl - 5- oxo-Delt6 (8)- tetrahydrochysene indolizine and haloethane reacts with each other for ethylization with existence of alkali and organic solution with or without phase transversion catalyst, and produces mentioned product.

本发明在相转移催化剂或无相转移催化剂存在下，6-氰基-1，1-(1，3-亚丙二氧基)-7-(甲氧羰基-甲基-5-氧代-Δ6(8)-四氢中氮茚类化合物与卤代乙烷在碱和有机溶剂的存在下进行乙基化反应即得6-氰基-1，1-(1，3-亚丙二氧基)-7-1′-(烷氧羰基-丙基-5-氧代-Δ6(8)-四氢中氮茚类化合物。

Synthesis technology of cinnamyl methyl fumarate containing α,β-unsaturated carbonyl group and its antimicrobial activity was studied.

以α，β-不饱和羰基结构为母体设计合成反丁烯二酸桂醇甲酯，并对反丁烯二酸桂醇甲酯的抗菌活性进行了研究。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。