乙酸乙酯

In particular, when the Knoevenagel condensation of 2-hydroxybenzaldehyde was conducted with ethyl 2-cyanoacetate, 3-ethoxycarbonylcoumarin was obtained by simultaneous cyclization and alcoholysis of cyanide.

当反应底物为水杨醛与氰基乙酸乙酯的时候，产物为3-乙氧基羰基香豆素，这是水杨醛和氰基乙酸乙酯缩合关环，再发生氰基醇解的产物。

Methods 4-Hydroxy- benzonitrile was treated with sodium hydrogen sulfide and anhydrous magnesium chloride in dimethyl formamide to give thioamide, which was then directly cyclized with ethyl 2-chloroacetoacetate without separation to give ethyl 2-(4-hydroxyphenyl)-4-methylthiazole-5-carboxylate(2) in one-pot; then 2 was formylated with Duff reaction adopting hexamethylenetetramine in trifluoroacetic acid to give ethyl 2-(3-formyl-4-hydroxyphenyl)-4-methylthiazole-5-carboxylate(3); finally, the target compound was obtained by the treatment of 3 with hydroxylamine hydrochloride and sodium formate in formic acid.

采用"一勺烩"方法，以4-羟基苯甲腈为起始原料，首先与硫氢化钠和无水氯化镁在N，N-二甲基甲酰胺中反应，所得中间体不经分离，直接加入2-氯乙酰乙酸乙酯进行环合反应，得到2-(4-羟基)苯基-4-甲基-5-噻唑甲酸乙酯（2）；然后通过六亚甲基四胺/三氟乙酸进行Duff反应，得到2-(3-甲酰基-4-羟基)苯基-4-甲基-5-噻唑甲酸乙酯（3）；再经盐酸羟胺/甲酸/甲酸钠体系脱水得到目标化合物。

The main esters in Chinese distilled liquor include,ethyl caproate,ethyl acetate,ethyl lactate and ethyl butyrate etc.

中国蒸馏酒中含有一定比例的乙酸乙酯、乳酸乙酯、己酸乙酯和丁酸乙酯等，这几种酯的含量在一定程度上形成了中国蒸馏酒与外国蒸馏酒很不相同的地方。

The results showed that there were 8 kinds of aliphatic, 5 kinds of esters, 2 kinds of aldehydes, 2 kinds of nitrogen sulfur heterocyclic rings and one kind of hydrocarbon, alcoholics, ketone, lactones respectively in the analyzed 21 kinds of aroma components, and the content of furfural,β-methyl valeric acid, palmitic acid, nicotine, neohytadiene were higher, next were acetyl ethyl propionate, caleric acid, phenyl ethyl acetate, hydroxylic diethyl succinate.

结果表明，在分析出的21种香气成分中，分别有脂肪酸类8种，酯类5种，醛类2种，氮硫杂环类2种，烃类、醇类、酮类、内酯类各l种，其中相对含量较高的物质成分是糠醛、β-甲基戊酸、十六碳酸、烟碱、新植二烯，其次是乙酰丙酸乙酯、异戊酸、苯乙酸乙酯、羟基丁二酸二乙酯等。

Objective To determine the contents of residual acetone in acetoacetic ester,the raw material for the synthesis of Edaravone, by gas chromatography.Methods Sample solution was injected on a GDX column (0.18 mm～0.25 mm) with nitrogen as the carrier gas.The residue was calculated by the external standard method.

摘要］ 目的：用气相色谱法测定依达拉奉合成起始原料乙酰乙酸乙酯中丙酮的残留量方法：采用固定相二乙烯苯乙基乙烯苯型高分子孔小球（直径为0.18 mm～0.25 mm），氮气为载气，用外标法测定乙酰乙酸乙酯中残留丙酮的含量。

Purified water, euphorbia cerifera wax, glyceryl stearate, ammonium acrylates copolymer, butylene glycol, copernica cerifera wax, stearic acid, sucrose acetate isobutyrate, acrylates copolymer, bentonite, tromethamine, hexylene glycol, silk amino acids, cholesterol, glycine, synthetic wax, ethylhexyl glycerin, alanine, PEG-9 dimethicone, nylon-6, lecithin, silica, simethicone, caprylyl glycol, xanthan gum, propylene glycol, isostearic acid, sodium laureth-12 slfate, ceteareth-20, polyvinyl alcohol, sodium chloride, sodium acetate, disodium EDTA, benzyl alcohol, chlorphenesin, phenoxyethanol, methylparaben, ethylparaben, propylparaben, butylparaben, isobutylparaben, may contain /- mica, iron oxides (CI 77491, CI 77492, CI 77499), titanium dioxide (CI 77891), ferric ferrocyanide (CI 77150), ultramarines (CI 77007), blue 1 lake (CI 42090), bronze powder (CI 77400), aluminum powder (CI 77000), bismuth oxychloride (CI 77163), carmine (CI 75740), chromium hydroxide green (CI 77289), chromium oxide greens (CI 77288), yellow 5 lake CI 19140

水，小烛树蜡，硬脂酸甘油酯，丙烯酸铵共聚物，1，3-丁二醇，巴西棕榈蜡，硬脂酸，异丁酸醋酸蔗糖酯，丙烯酸酯共聚物，蒙脱土，二吡喃乙酸乙酯胺，已烯醇，丝氨酸，胆固醇，甘油，合成蜡，异丁基甘油，丙胺酸，PEG-9二甲基硅油，尼龙-6，卵磷酯，硅粉，硅氧烷，癸酰基乙二醇，汉生胶，丙二醇，异硬脂酸，月桂基醚-12硫酸钠，十六十八醇醚-20，聚乙烯醇，氯化钠，醋酸钠，EDTA二钠，苯氧乙醇，氯代苯酚，卞醇，尼泊金甲酯，尼泊金乙酯，尼泊金丙酯，尼泊金丁酯，尼泊金异丁酯，[可能还含有云母，铁黑(CI 77491， CI 77492， CI 77499)，钛白粉(CI 77891)，氰化亚铁(CI 77150)，靛蓝(CI 77007)，蓝1号(CI 42090)，青铜粉(CI 77400)，铝粉(CI 77000)，氯氧化铋(CI 77163)，洋红色素(CI 75740)，氢氧化铬绿(CI 77289)，氧化铬绿(CI 77288)，黄5号(CI 19140)]文章来自网络，不代表本网站立场，版权归原作者所有，转载请注明出处！

Results: The 12 kinds of toxicants including methyl acetate, ethyl acetate, benzene, toluene, ethylbenzene, butyl acetate, p-dimethylbenzene, m-dimethylbenzene, o-dimethylbenzene, n-butanol, cinnamene and cyclohexanone were separated well. Good linear relationship sensitivity and reproducibility were obtained and detection limits (S/N=3) of them were 0.2 mg/l respectively. Conclusion: In this paper, a new method for simultaneous determination of 12 kinds of toxicants by using gas chromatography has been described.

结果：对乙酸甲酯、乙酸乙酯、苯、甲苯、乙酸丁酯、乙苯、对二甲苯、间二甲苯、邻二甲苯、正丁醇、苯乙烯、环己酮12种有毒物质的分离效果好，线性和重现性均较好，方法的检测限达到0.2 mg/L。

The first synthetic route uses 1,2,4-trimethoxybenzene and chloroacetonitrile in forming 2,4,5-trimethoxy-a-chlor-acetophenone under the anhydrous condition, then the intermediate condensates with papaverine forming the core pyrro[2,l-a]isoquinoline, followed by formation and lactonization to form the lactone ring. The second synthetic route uses prepared aldehyde with prepared ethyl nitroacetate by Knoevenagel condensation to obtain 2-Nitro-3-(2,4,5-tris-methoxy-phenyl)-acrylic acid ethyl ester and 2-Nitro-3-(2,4,5-tris-benzyloxy -phenyl)-acrylic acid ethyl ester etal intermediates. The lamellarin skeleton could arise from condensation of the papaverine and these intermediates by Michael reaction, the ester group is provided for subsequent lactonization. The third synthetic route uses coumarin or indan-l,3-dione derivatives and papaverine to form lamellarin under basic conditions.

第一条路线首先从1，2，4-三甲氧基苯出发与卤乙腈作用合成卤代芳酮中间体，然后与罂粟碱反应合成开链片螺素，最后经乙酰化、去保护、成内酯环得到片螺素；第二条路线由制备的芳醛和制备的硝基乙酸乙酯经缩合得到2-硝基-3-芳基丙烯酸乙酯，然后由该中间体与罂粟碱反应，在完成关环的同时也引入酯基，最后去保护、成内酯环得到片螺素；第三条路线是由香豆素或茚二酮出发，经溴代后的中间体与罂粟碱反应，得到片螺素的基本框架。

Methods 4-Hydroxy- benzonitrile was treated with sodium hydrogen sulfide and anhydrous magnesium chloride in dimethyl formamide to give thioamide, which was then directly cyclized with ethyl 2-chloroacetoacetate without separation to give ethyl 2-(4-hydroxyphenyl)-4-methylthiazole-5-carboxylate(2) in one-pot; then 2 was formylated with Duff reaction adopting hexamethylenetetramine in trifluoroacetic acid to give ethyl 2-(3-formyl-4-hydroxyphenyl)-4-methylthiazole-5-carboxylate(3); finally, the target compound was obtained by the treatment of 3 with hydroxylamine hydrochloride and sodium formate in formic acid.

采用&一勺烩&方法，以4-羟基苯甲腈为起始原料，首先与硫氢化钠和无水氯化镁在N，N-二甲基甲酰胺中反应，所得中间体不经分离，直接加入2-氯乙酰乙酸乙酯进行环合反应，得到2-(4-羟基)苯基-4-甲基-5-噻唑甲酸乙酯（2）；然后通过六亚甲基四胺/三氟乙酸进行Duff反应，得到2-(3-甲酰基-4-羟基)苯基-4-甲基-5-噻唑甲酸乙酯（3）；再经盐酸羟胺/甲酸/甲酸钠体系脱水得到目标化合物。

At first, the broth was acidified, then centrifuged to get mycelia, which was heated and powdered; finally we use acetic ether to soak the powder. After that, the phase of acetic ether was washed using the solution of ammonium sulfate and the solution of ethanedioic acid, then concentrated to gain pulps. It was crystallized at 4℃.The coarse crystals was decolorized by activated carbons, the pure needle crystal of lovastatin was obtained.

发酵液经酸化处理后，离心得到菌体，烘干后过筛得到菌粉；用乙酸乙酯浸泡，乙酸乙酯相需用(NH_4)_2SO_4溶液和草酸溶液洗涤两次；乙酸乙酯相经薄膜浓缩得到浆状物，于4℃结晶，得到粗晶体；再经粉末活性炭脱色和重结晶后得白色针状结晶，为lovastatin的纯品。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。