查询词典 imidazole

One of them can efficient catalysed the alkene in the absence of dear additives by introducing an imidazole in the salen ligand.

其中分子内含咪唑的手性吡咯烷Mn催化剂成功实现了不加昂贵添加剂的情况下高效催化取代色烯环氧化反应。

For the synthesis of NHC precursors, there are also several routes: condensation of glyoxal, amines and paraformaldehyde; alkylation of imidazole or monosubstituted imidazole with alkyl halide; annulation of ortho esters and 1,2-diamines; ring closure of hydrazines or amides with acetic anhydride; reduction of thiones with Na/K in THF.

关于N-杂环卡宾前体的合成途径主要有：乙二醛、伯胺和多聚甲醛的缩合反应；卤代烷与咪唑及其取代咪唑的烷基化反应；原甲酸酯与1，2-二胺的成环反应；肼或酰胺与酸酐的环化反应；用Na/K对环硫脲化合物的还原反应。

Based on the available crystal structures of MMPs, the structure-activity relationship of barbiturate compounds was discussed; and the reason for imidazole-based compounds'low activity was presented.

本文结合已有的晶体结构，对巴比妥酸类作了初步的构效关系探讨，并对咪唑类化合物活性低的原因进行了初步分析，对进一步的结构改造和合理设计具有一定的指导意义。

Ethyl 4-[(1-hydroxy-1-methyl)ethyl]-2-propyl-1H-imidazole-5-carboxylate,the key intermediate of Olmesartan ,was synthesized from butanoic acid and o-phenylenediamine via condensation under microwave-irradiation,oxidation,esterification and the Gringard reaction.

用正丁酸与邻苯二胺为原料，在微波照射下缩合成2-丙基苯并咪唑，再氧化开环制得2-丙基咪唑二羧酸，再经酯化、Gringard反应制得抗高血压药物奥美沙坦的关键中间体2-丙基-4-[(1-羟基-1-甲基)乙基]-1H-咪唑-5-羧酸乙酯，总收率32.2%。

This paper also discovered that the phosphoryl transfer reactions of Nphosphoamino acids were catalyzed by imidazole with factors of 10-38, and the catalytic reaction rates could be influenced by the concentration of imidazole, structure of amino acids and alcohol.

磷酰化氨基酸的分子内N→O磷酰基转移反应具有很强的立体效应，丝氨酸与高丝氨酸，苏氨酸与来苏氨酸的反应活性分别相差6倍和1倍左右。

The ammonia was evaporated under decreasing pressure, and the precipitate was filtered off and the liquid was poured into hot saturated picric acid solution to get picrate with a yield of 85.0%. The optimum process starting from imidazole-4,5-dicarboxylic acid was: imidazole-4,5-dicarboxylic acid in acetic anhydride was refluxed to get imidazole-4-carboxylic acid, and the product was esterification in ethanol with a catalyzer of concentrated sulfuric acid to get ethyl imidazole-4-carboxylate, at last the compound above was reduced by LiAlH4 in ether at room temperature to get the target compound, the total yield of this route was 49.6%.

以4，5-二羧酸咪唑为原料的较佳工艺：1 脱羧反应：4，5-二羧酸咪唑40g，醋酐1200ml，回流10h，过滤并将滤液浓缩至干，所得固体加至50%的乙醇溶液回流，过滤并将滤液自然冷却过夜，过滤得固体；2 酯化反应：4(5)-羧酸咪唑50g，乙醇1000ml和浓硫酸60ml，加热回流2h，5%浓度NaOH溶液调节至pH＝8，减压浓缩至干，加入少量水回流，自然冷却过夜并过滤得固体；3 还原反应：LiAlH410g，乙醚300ml和4(5)-羧酸咪唑乙酯28g，常温反应1.5h，小心滴加25ml水后过滤，滤渣溶于300ml甲醇中并过滤，收集所得乙醚和甲醇滤液浓缩至干，将所得固体溶于300ml乙醇中加热回流，后将溶液浓缩至约30ml，冷却并过滤得固体，该路线总收率为49.6%。

Two synthetic routes starting from 1,3-dihydroxyacetone and formamidine acetate as well as imidazole-4,5-dicarboxylic acid as starting material were investigated, and the reductive reaction of ethyl imidazole-4-carboxylate was also investigated.

本文对以1，3-二羟基丙酮和醋酸甲脒为原料和以4，5-二羧酸咪唑为原料合成4(5)-羟甲基咪唑的两条工艺进行了研究并优化，同时对4(5)-羧酸咪唑乙酯的还原反应进行了探索性实验。

Dihydroxyacetone; formamidine acetate; imidazole-4,5-dicarboxylic acid; optimizing process; ethyl imidazole-4-carboxylate; reductive reaction; 4(5)-hydroxymethylimidazole

关键字或关键词组： 1，3-二羟基丙酮；醋酸甲脒；4，5-二羧酸咪唑；工艺优化；4(5)-羧酸咪唑乙酯；还原反应；4(5)-羟甲基咪唑

As for the ester exchange reaction on phosphorus, it was found that N-phosphoryl histidine the fastest one among all of the N-phosphoryl aminoacids. The results studied by MNDO method indicate that due to theparticipation of imidazole group, the formation of hexa-coordinatephosphorus intermediate made the iso-propoxyl which is opposite toimidazole group more active than the other ones and much easier to leave.When iso-propoxyl left, a new penta-coordinate phosphorus intermediate wasformed, and it is sterically favorable to be attacked by an alcohol from theopposite direction of imidazole.

对于磷上酯交换反应，实验中发现N-磷酰组氨酸反应速度明显高于其它N-磷酰氨基酸，理论研究表明，侧键咪唑基参与下六配位磷中间体形成后，位于咪唑基对面的异丙氧基反应活性大大提高，即从咪唑基的对面位置发生异丙氧基的离去和另一分子醇的进攻，在能量上和空间上都是有利的。N-磷酰丝氨酸的磷上酯交换反应有着类似的特点。

Two new chiral imidazoles with big conjugate system were synthesized, that is,-1-(-methylbenzyl)-2-benzene-4,5-dibenzene-imidazole and-1-(-methyl benzyI)-2-styrene-4,5-dibenzene-imidazole, whose salifying conditions were also briefly investigated.

设计并合成了两个新的含有手性单元和较大共轭体系的多取代咪唑：-1--2-苯基-4，5-二苯基咪唑和-1--2-苯乙烯基-4，5-二苯基咪唑，并对其成盐反应和条件进行了一些初步研究。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。