N-苄基甘氨酸乙酯合成及应用研究进展

叙述了国内外N-苄基甘氨酸乙酯的几种化学制备方法,即分别以卤代乙酸乙酯、甘氨酸乙酯、叠氮乙酸乙酯和乙醛酸乙酯乙基半缩醛为起始原料的合成工艺.并介绍了N-苄基甘氨酸乙酯在农业、医药、化工等行业中合成有机中间体方面的应用情况.     

N-苄基甘氨酸乙酯合成及应用研究进展

叙述了国内外N-苄基甘氨酸乙酯的几种化学制备方法,即分别以卤代乙酸乙酯、甘氨酸乙酯、叠氮乙酸乙酯和乙醛酸乙酯乙基半缩醛为起始原料的合成工艺.并介绍了N-苄基甘氨酸乙酯在农业、医药、化工等行业中合成有机中间体方面的应用情况.     

N-苄基甘氨酸乙酯合成及应用研究进展

叙述了国内外N 苄基甘氨酸乙酯的几种化学制备方法,即分别以卤代乙酸乙酯、甘氨酸乙酯、叠氮乙酸乙酯和乙醛酸乙酯乙基半缩醛为起始原料的合成工艺。并介绍了N 苄基甘氨酸乙酯在农业、医药、化工等行业中合成有机中间体方面的应用情况。     

几种氨基酸的合成研究

1不对称相转移催化合成L-苯丙氨酸 化学合成法制备L-苯丙氨酸主要有苯甲醛与乙甘氨酸缩合法与氰氨法,这两种方法工艺路线长、收率低。工业上L-苯丙氨酸主要从天然产物中提取。利用不对称合成反应由化学法合成L-苯丙氨酸一直是化学工作者关注的课题。南京理工大学化工学院的周凤儿和魏运洋以（＋）-N-苄基氯化辛可宁作为手性相转移催化剂,以甘氨酸乙酯盐酸盐和溴化苄为基本原料,合成了L-苯丙氮酸。     

N-苄基苦参酰甘氨酸的合成

目的:合成N-苄基苦参酰甘氨酸。方法:以苦参碱为原料,经水解、苄基化、水解等反应得到N-苄基苦参酸,然后利用其结构上的羧基,与甘氨酸甲酯盐酸盐缩合形成N-苄基苦参酰甘氨酸甲酯,再进一步水解生成N-苄基苦参酰甘氨酸。结果与结论:合成得到目标化合物,其结构经MS、IR、1H-NMR等方法确证,产物收率为74.4%(以N-苄基苦参酸计)。     

N-甲基氰胺基甲酸乙酯合成中相转移催化剂的使用

考察了苄基三乙基氯化铵等7种相转移催化剂对N-甲基氰胺基甲酸乙酯N-甲基化反应的影响。确立了在同等反应条件下苄基三甲基氯化铵催化活性最高,当n(单氰胺)∶n(苄基三甲基氯化铵)=1.00∶0.03时,N-甲基氰铵基甲酸乙酯N-甲基化反应的收率达93.3%。     

菊酸乙酯工段重氮化反应工艺的改进

对菊酸乙酯工段重氮化反应工艺进行了技术改进，使该工艺流程中环化液的菊酸乙酯含量稳定在１３％以上，甘氨酸乙盐酸盐的消耗下降到１．４５。     

几种氨基酸的合成研究

L-苯丙氨酸是人体必需的氨基酸之一，在医药、食品领域用途广泛，可用于生产口服或注射用氨基酸片和氨基酸营养液，是多种抗癌和抗病毒药物及甜味剂阿斯巴甜的原料。化学合成法制备L-苯丙氨酸主要有苯甲醛与乙甘氨酸缩合法与氰氨法，这两种方法工艺路线长，收率低。工业上L-苯丙氨酸主要从天然产物中提取。利用不对称合成反应由化学法合成L-苯丙氨酸一直是化学工作者关注的课题。南京理工大学化工学院的周凤儿和魏运洋以（＋）-N-苄基氯化辛可宁作为手性相转移催化剂，以甘氨酸乙酯盐酸盐和溴化苄为基本原料，合成了L-苯丙氨酸。     

N-(3-甲酰基苯基)甘氨酸衍生物的合成

从苯甲醛和茴香醛出发,分别经过5步反应合成了N-(3-甲酰基苯基)甘氨酸乙酯和N-(2-甲氧基-5-甲酰基苯基)甘氨酸乙酯。对N-(3-甲酰基苯基)甘氨酸乙酯和N-(2-甲氧基-5-甲酰基苯基)甘氨酸乙酯进行乙酰化,然后水解酯基,可分别得N-乙酰基-N-(3-甲酰基苯基)甘氨酸和N-乙酰基-N-(2-甲氧基-5-甲酰基苯基)甘氨酸。这些产物的结构均由1HNMR、13CNMR、HRMS和IR进行了表征。     

乙酰甘氨酸乙酯的合成研究

以甘氨酸为原料,先利用酰化反应合成乙酰甘氨酸,然后在HCl气体催化下使乙醇与乙酰甘氨酸反应合成乙酰甘氨酸乙酯。研究了催化剂用量、配料比、反应温度和反应时间对酯化反应收率的影响。     

氯亚乙基肼基甲酸乙酯生成反应热动力学研究

利用微量热量计测定了氯乙醛和肼基甲酸乙酯在水溶液中(298.15K)生成氯亚乙基肼基甲酸乙酯的反应焓变为(-13.035±0.088)kJ/mol。计算得出该反应的热动力学参数:反应级数n=1;速率常数k=2.018×10-3s-1及反应活化自由能ΔG ≠=88.408kJ/mol。结果表明,该反应在室温下易于进行。     

哈格曼乙酯与硝基乙烷在不同碱催化下的迈克尔加成反应

研究了在不同有机碱催化下,哈格曼乙酯和硝基乙烷经迈克尔加成合成3 甲基 3 (1′ 硝基乙基) 4 乙氧甲酰环己酮的反应。结果表明,氟化四丁基铵的催化效果最好,且当n(氟化四丁基铵)∶n(哈格曼乙酯)=1∶2时,合成产物3 甲基 3 (1′ 硝基乙基) 4 乙氧甲酰环己酮的收率达到最高值56%。     

酯交换法合成L-抗坏血酸棕榈酸酯的工艺改进

以L—抗坏血酸和棕榈酸乙酯为原料，H2SO4为催化剂，酯交换法合成L—抗坏血酸棕榈酸酯。研究了L—抗坏血酸与棕榈酸乙酯的物质的量比、催化剂浓度、反应温度、反应时间等工艺条件对产率的影响。工艺条件优化后，产率达到75％，产品质量符合GB16314——1996标准。     

正己酸二乙氨基乙酯的合成及反应动力学

[目的]以正己酸和二乙氨基乙醇为原料,阳离子交换树脂催化合成正己酸二乙氨基乙酯.考察了反应过程的影响因素,测定了动力学数据.[结果]合成工艺条件,n(正己酸):n(二乙氨基乙醇)为2.0:1,催化剂用量为正己酸和二乙氨基乙醇总质量的2%,甲苯用量为正己酸和二乙氨基乙醇总体积的110%,反应温度不超过130℃,反应时间3.0 h,二乙氨基乙醇的转化率达95.6%,催化剂重复使用4次后,二乙氨基乙醇的转化率为92.8%.表观活化能为73.219 kJ/mol,指前因子为1.9323×107L/(mol·min).[结论]阳离子交换树脂具有较好的催化活性和稳定性,该酯化反应对正己酸和二乙氨基乙醇均为一级反应.     

Syntheses of cellulose exchangers carrying chelating anchor groups for selective separation of uranyl ions

Syntheses of cellulose exchangers carrying tailor-made chelating anchor groups are described. One type of anchor groups offers three coplanar carboxy groups for the complexation of UO²⁺₂, a second type coplanar amidoxime-hydroxamic acid groups and a third type amidrazone-hydrazide groups. The distance of the groups is varied by use of different terminal dibromo-n-alkanes. The anchor groups of type 1 are obtained from malonic acid diethyl ester and dibromalkanes, type 2 and 3 from cyanacetic acid ethylester and dibromoalkanes. The products containing malonic acid diethylester and alkane groups or cyanoacetic acid ethylester and alkane groups, respectively, in the mole ratio 3 : 2 are coupled with hydrazinedesoxycellulose. The carboxy groups are set free by hydrolysis of the ethyl esters in case of type 1, whereas the anchor groups of types 2 and 3 are obtained by reaction with hydroxylamine and with hydrazine, respectively. The procedures of the syntheses are presented in detail. The products are characterized by the degree of substitution and the content of the individual groups. The anchor groups are inverstigated by means of their ¹H-NMR spectra. The exchange properties are discussed.     

Examples of peptide-peptoid hybrid serine protease inhibitors based on the trypsin inhibitor SFTI-1 with complete protease resistance at the P1-P1' reactive site

Research in the field of protease inhibitors is focused on obtaining potent, specific and protease-resistant inhibitors. To our knowledge, there are no reports in the literature that consider the application of N-substituted glycine residues (peptoid monomers) for the design of peptidomimetic protease inhibitors. We hereby present the chemical synthesis and kinetic properties of two new analogues of the trypsin inhibitor SFTI-1 modified at the P1 position. Substitution of Lys5 in SFTI-1 by N-(4-aminobutyl)-glycine and N-benzylglycine, which mimic Lys and Phe, respectively, made these analogues completely protease-resistant at their P1-P1' reactive sites. The analogues synthesised appeared to be potent inhibitors of bovine beta-trypsin and alpha-chymotrypsin. These noncovalent, competitive and selective peptide-peptoid hybrid (peptomeric) inhibitors might open the way to targeting unwanted proteolysis.     

Etude de la reduction sur electrode de mercure de thioethers et de sulfoniums derives de l'acide β-mercaptopyruvique

Thioethers with general formula RSCH₂COCOOR′ where R is paratolyl, methyl or ethyl, and sulfonium salts like Br^?,(CH₃)₂$\text{S}\text{+}$-CH₂COCOOR′ which proceed from β-mercaptopyruvic acid or its ethylester, have been investigated polarographically and by means of controlled potential electrolysis, in aqueous or aquo—alcoholic media.Reduction of sulfonium salts at the mercury electrode is in accordance with the general rule a reductive cleavage of the substituting group RS— occurs. Behaviour of thioethers is not uniform. When R is aryl, cleavage of the carbone—sulphur bond still occurs; when R is alkyl, the carbonyl group undergoes the reduction and the substituted secondary alcohol is formed.     

乙苯合成新技术—乙醇制乙苯

介绍了几种乙苯生产技术,重点介绍了乙醇制乙苯新技术及其应用情况,如山东菏泽玉皇化工有限公司的20万t/a苯乙烯装置乙苯单元采用乙醇与苯直接分子筛气相烷基化制乙苯技术,随着装置的开车成功标志着国内首套乙醇制乙苯技术首次实现工业化.目前装置运行平稳,各项指标均达到设计要求,经济效益显著.     

EFFECT OF CHEMICAL PRETREATMENT ON THE PHYSICAL PROPERTIES OF DEHYDRATED GRAPES

The effects of chemical pretreatment and air drying temperature on drying kinetics, shrinkage, density and rehydration ratio of grapes were determined at various moisture contents. It was observed that the chemical pretreatment employed - a solution of 2% CaCCb with 0 to 3% ethyl oleate - increased considerably the drying rate. It was established that the shrinkage increased with drying temperature between 40 to 80°C and decreased with increasing concentration of ethyl oleate in the chemical pretreatment solution.