乙酯

Eleven novel 2-alkylthio-5-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-5-yl)-1,3,4-oxadiazole derivatives (5) and six novel 2-alkylthio-5-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-5-yl)-1,3,4-thia- diazole derivatives (8) have been designed and synthesized by using 5-amino-3-ethoxycarbonyl-1H-1,2,4-triazole as a starting material.

以5-氨基－1H-1，2，4-三唑－3-羧酸乙酯为起始原料，设计合成了11个新型的2-取代硫醚－5-（5，7-二甲基－1，2，4-三唑并[1，5-a]嘧啶基）-1，3，4-恶二唑类化合物(5)和6个新型的2-取代硫醚－5-（5，7-二甲基－1，2，4-三唑并[1，5-a]嘧啶基）-1，3，4-噻二唑类化合物(8)。

The intermediate of flazasulfuron weedicide ,2-amino-4,6-dimethoxypyrimidineis conveniently obtained by treating 2-amino-4,6-dihydroxypyrimidinewith diazomethane at 20 °C for 24h.

本文利用硝酸胍和丙二酸二乙酯为起始原料，经环合及甲氧基化两步反应得到除草剂啶嘧磺隆的中间体：2-氨基-4，6-二甲氧基嘧啶。

Herein, we report the enantioselective total syntheses of slagenins A-C and their antipodes. Starting from readily available ethyl -4-chloro-3-hydroxy-butanonate, elongation of the carbon chain with diazomethane, followed by oxidation of the given α-diazoketone using distilled DMD, afforded a key intermediate α-ketoaldehyde .

本文从方便易得的-4-氯-3-羟基-丁酸乙酯出发，经重氮甲烷延伸碳连、DMD氧化相应的α-重氮酮，制得α-酮醛；该化合物与尿素在氢氟酸作用下，以协同方式非对映选择性的直接构建了cis-四氢呋喃并[2，3-d]咪唑啉-2-酮双环结构，进而合成了天然产物slagenins A、B、和C的对映体。

The velocities of reaction of ethyl acetate with sodium hydroxide in dioxane- water mixture have been determined in seven different temperatures(5°,10°, 15°,20°,25°,30°and 35°).

作者在7具不同温度(5°，10°，15°，20°，25°，30°，35°)下，研究了乙酸乙酯和氢氧化钠在二氧六圜和水的混合溶剂中的反应速度。

Dioxane was selected as solvent. The linear range for methanol was 6-54mg/L for ethanol and ethyl acetate both were 10-90mg/L. The average recovery of them was 99, 36, 101.26% and 101.57% respectively.

在上述色谱条件下，甲醇的线性范围为6-54mg/L，乙醇和乙酸乙酯的线性范围为10-90mg/L；平均加样回收率分别为99.36、10l.26%和101.57%。

Object: The antimicrobial effects of the water, 60% alcohol, 90% alcohol extract and petroleum ether, ethyl acetate, n-butanol components from Pomegranate rind against 3 kind of pathogenesis bacterial and 14 kind of epiphyte were accomplished.

目的：对石榴皮的水、60%乙醇、90%乙醇提取物以及石油醚、乙酸乙酯、正丁醇萃取物对3种细菌和14种真菌的体外抗菌试验进行了研究。

In addition, the Gibbs free energy and standard equilibrium constant of the reaction were calculated under the different temperature.

采用基团贡献法估算了反应体系中乙酸、乙醇和乙酸乙酯在298.15K标准状态下的生成焓和标准熵，并且估算了这3种物质的热容随温度变化的关系式，计算了不同温度条件下反应的吉布斯自由能和标准平衡常数。

At the same time, the results showed that silver ion can not complex with oleic acid ethyl ester.

同时，本研究还表明，银离子不能与油酸乙酯形成络合物。

Its catalytic activity in the esterification to form ethylacetate was investigated with the highest yield of 96.2%.

在乙酸乙酯的合成反应中考察了该催化剂的催化活性。

It is the first time that the petroleum ether extract and ethyl acetate extract of Nerviliafoadii.

首次确定了青天葵的石油醚和乙酸乙酯部位是体内抗肿瘤作用的有效部位。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。