对氰基苯甲酸乙酯的合成研究

以对氨基苯甲酸乙酯为原料，经重氮化反应及Sandmeyer的氰化反应制得对氰基苯甲酸乙酯，对重氮盐的制备及氰化过程进行了研究，简化了操作，提高了产物收率。     

对硝基苯甲酸乙酯的合成

以硫酸氢钾为催化剂,研究了对硝基苯甲酸和乙醇反应生产对硝基苯甲酸乙酯的合成工艺.考察了催化剂用量、反应时间、醇酸物质的量之比、带水剂用量以及催化剂重复使用次数对酯化率的影响,确定了最佳反应条件.当对硝基苯甲酸的用量为0.015mol,无水乙醇为0.060mol,反应时间为2.0h,带水剂环己烷用量为15mL,催化剂硫酸氢钾的用量为0.4g,对硝基苯甲酸乙酯的酯化率可达到91.65%.在此条件下,催化剂的催化活性高,反应条件温和,该合成方法简便,产品收率优良,催化剂可重复使用,且价格低廉.     

离子液体催化合成对羟基苯甲酸乙酯

采用酸性离子液体[C3SO3 Hmim] HSO4、[C4SO3 Hmim] HSO4和[C3SO3 Hnhm] HSO4代替浓硫酸为催化剂合成对羟基苯甲酸乙醇.考察了反应温度、反应时间、催化剂用量、酸醇摩尔比对该反应产率的影响及离子液体的重复使用性能.选择了最佳反应条件,以[C3SO3 Hnhm] HSO4作为催化剂...     

苯甲酸乙酯合成实验的改进

引入微波技术,对以硫酸为催化剂,水浴回流分水制备苯甲酸乙酯的传统方法进行合理改进,重点考察微波功率、反应温度、反应时间对产率的影响。采用正交设计安排实验,实验结果经过优化组合,得出最佳反应条件为：辐射时间15 min,微波功率600 W,反应温度95 ℃。利用微波辐射加热方式替代普通的沸水浴合成苯甲酸乙酯,达到缩短反应时间,提高反应效率的目的,产物用减压蒸馏分离纯化,整个实验教学具有绿色化、现代化和综合化的特点,有利于提高学生实验兴趣,同时保证了在有限的实验时间内有充足的知识点和充分的技能训练。     

对硝基苯甲酸乙酯合成方法的改进

对硝基苯甲酸乙酯合成方法的改进申东升，林原斌，张亚利，韩安斌（湘潭大学化学系，４１１１０５）对硝基苯甲酸乙酯是合成苯佐卡因、盐酸普鲁卡因等麻醉药剂的医药中间体，是一种用于防止皮革制品、软塞产品和某些颜料霉变的最有效的杀菌剂。已报道的几种催化合成法存在...     

三(对氰基苄基)氯化锡的合成及晶体结构研究

苄基锡化合物因其具有丰富的反应性、结构特征及抗癌活性而引起人们的兴趣,最近我们合成了一系列的卤代苄基锡化合物,并报导了它们的晶体结构。在研究中我们发现苯环上连有的取     

4 氨基4′ 氰基联苯的合成

４氨基４′氰基联苯,不仅是制备烷氧基联苯的原料,而且可以制备高正介电各向异性液晶及系列酯类液晶材料．但通常要经过酰化、氧化、酰氯化、氨解、脱水、硝化和还原［１］等多步反应,步骤长、收率低,本文用联苯为原料,经过硝化、碘代、氰代和还原反应合成４氨基４′氰基联苯．反应步骤及时间比原路线减少近一半,而且反应条件温和,收率高．联苯（ＣＰ,上海化学试剂一厂）;Ｎ,Ｎ二甲基甲酰胺（ＡＲ,临平化工试剂厂）;氯仿（ＡＲ,沈阳试剂一厂）;亚硫酸氢钠（ＡＲ,大连辽南化学品厂）;碘酸（ＡＲ,北京化工厂）…     

硫酸氢钠催化合成对羟基苯甲酸乙酯

在一水硫酸氢钠的催化作用下,对羟基苯甲酸和乙醇发生酯化反应,高收率地合成了对羟基苯甲酸乙酯.产品经红外光谱、气相色谱和质谱联用技术和溶点进行确定.     

苯甲酸乙酯合成实验的改进

采用改进的实验装置合成苯甲酸乙酯,简化了实验操作,提高了反应效率,消除了对环境造成的污染,并可实现少量或半微量合成。     

异硫氰基乙酸乙酯的合成

在碱性条件下，用氨基乙酸与二硫化碳、氯甲酸乙酯反应合成了异硫氰基乙酸乙酯，总收率为48．54％。     

4-取代-2-甲基-6,7-亚甲二氧基-3-喹啉酸乙酯的合成及表征

喹啉及其衍生物是合成抗疟药物和某些金属萃取剂的重要原料[1,2]。文献[3,4]曾报道2,3 二取代喹啉衍生物的合成方法。本文以1,2 亚甲二氧基苯为原料,通过酰化、硝化、还原和催化缩合,得到四种4 取代 2 甲基 6,7 亚甲二氧基 3 喹啉酸乙酯Ⅳ,产率为74～87%。化合物Ⅳa-Ⅳd分别通过IR、1HNMR谱、元素分析和质谱表征。合成路线如图1所示。R=a,CH3;b,C2H5;c,CH2CH2CH3;d,CH(CH3)2。图1　4 取代 2 甲基 6,7 亚甲二氧基 3 喹啉酸乙酯合成路线Fig.1　Syntheticroutenof4 substitrtedethyl 2 methyl 6,7 methylenedioxy 3 quinolinecar…     

Condensation of 4-chloro-2H-chromene-3-carbaldehydes and ethyl-3-aminocrotonates with p-TsOH: a facile approach for the synthesis of chromenyldihydropyridines

The investigated reaction of 4-chloro-2H-chromene-3-carbaldehyde 1a with ethyl 3-oxobutanoate 2a in the presence of ammonium acetate provided two compounds, 2H-chromenyldihydropyridine dicarboxylate 3a and chromenopyridine carboxylate 4a. However, the reaction of 1a with ethyl-3-aminocrotonate 5a in the presence of p-TsOH provided selectively 2H-chromenyldihydropyridine dicarboxylate 3a with very good yield. The established method was applied for the preparation of series of 2H-chromenyldihydropyridine dicarboxylates 3a–q.     

面包酵母催化水相合成手性2-羟基-4-苯基丁酸乙酯的研究

手性醇是合成众多手性药物的中间体[1],手性2-羟基-4-苯基丁酸乙酯(HPBE)是血管紧张肽-转化酶抑制剂普利系列的关键手性中间体,已有许多相关制备方法的报道[2,3]。利用微生物或酶将前手性α-氧代酯类化合物不对称还原为手性α-羟基酯类化合物是较有应用前景的方法之一[4,5]。由     

新型4-羟基香豆素衍生物的合成

以DMSO为溶剂,碳酸二乙酯为酰化试剂,4-取代-2-羟基苯乙酮在氢化钠的催化下,经一步反应合成了7个新型的7-取代-4-羟基香豆素,产率49%~90%,其结构经1H NMR表征。     

A new reagent, 2-[phenyl(methyl)sulfonio]ethyl-4-nitro-phenylcarbonate tetrafluoroborate (Pms-ONp), for preparing water-soluble N-protected amino acids

Peptide syntheses are performed in various organic solvents, the disposal of which is an environmental problem. To avoid this problem, peptide synthesis in water using reagents of low toxicity is desirable. For peptide synthesis in water, we previously reported the design of a water-soluble N-protecting group, 2-[phenyl(methyl)sulfonio]ethoxycarbonyl tetrafluoroborate (Pms) group, but the introduction of this group onto sulfur-containing amino acids was problematic. Here, a new reagent, 2-[phenyl(methyl)sulfonio]ethyl-4-nitrophenylcarbonate tetrafluoroborate (Pms-ONp), has been designed and used to prepare Pms derivatives of sulfur-containing amino acids. Pms-Met was prepared and tested for the solid-phase synthesis of Met-enkephalin amide in water using a crosslinked ethoxylate acrylate resin.     

A simple and efficient synthesis of optically pure 4-alkylisoxazolidin-4-ols

The reaction between N-hydroxyphthalimide and optically pure epichlorohydrin followed by addition of methanol represents a straightforward procedure for the synthesis of isoxazolidin-4-ols in high enantiomeric purity. Under the same conditions, the reaction of glycidyl arenesulfonates can lead to different products depending on the nature of the sulfonate. This property allowed the synthesis of both enantiomers of 4-methylisoxazolidin-4-ol from the same chiral epoxide starting material.     

新型4-氨基喹唑啉衍生物的合成及其抗肿瘤活性

以香草醛为起始原料,与1-溴-3-氯丙烷经烷基化反应后,再与盐酸羟胺反应制得4-(3-氯丙氧基)-3-甲氧基苯腈(3);3经硝酸硝化、铁粉还原后,与N,N-二甲基甲酰胺二甲缩醛反应制得N-[5-(3-氯丙氧基)]-2-腈基-4-甲氧基苯基-N,N-二甲基甲酰胺(6);6与3-氯-4-氟苯胺合环后与芳香醚经取代反应合成了7个新型的4-氨基喹唑啉衍生物(9a~9g),其结构经1H NMR,13C NMR,IR和元素分析表征。初步生物活性测定结果表明:在用药量为10μmol·L-1时,N-(3-氯-4-氟苯基)-7-[3-(2-氯基苯氧基)丙氧基]-6-甲氧基喹唑啉-4-胺(9d)和5-氯-2-【3-{4-[(3-氯-4-氟苯基)胺]-6-甲氧基喹唑啉}-7-氧丙氧基】苯甲醛(9g)对人乳腺癌细胞Bcap-37的抑制率分别为61.4%和78.9%。     

Novel route to the synthesis of 4-quinolyl isothiocyanates

4-Quinolyl isothiocyanates were synthesized in a regiospecific fashion from the corresponding 4-chloroquinolines and silver thiocyanate in refluxing toluene. The products were isolated in quantitative yield and high purity (>95%) by simple filtration and concentration. Reactivity and mechanism of the reaction are discussed. The new approach would provide a new mean which had been lacking for the synthesis of functionalized 4-quinolinyl isothiocyanate.     

Parallel synthesis of 4-amino-2,6-dialkylamino-pyridines

In this Letter a fast and useful parallel synthesis approach to 4-amino-2,6-dialkylamino-pyridines is described starting from commercially available 2,6-difluoro-3,5-dichloro-pyridine. Both symmetrical and unsymmetrical derivatives have been synthesized respectively in two or three steps in good yields. The method described is mild, adaptable to combinatorial purposes and applicable to a variety of amines.     

Regioselective Synthesis of Two Novel 4-alkenyloxy-2,6-dihydroxyacetophenones

Thephenolscontainingalkenylunitslarealargegroupofinterestingnaturalproductsexhibitingmanyphysiologicalfunctionssuchasantiflammatory,antibacterialandantioxidativeactivities2.Twonovelacetophenones1and2wererecentlyisolatedfromthefruitsofEvodiamerrillii,asmallfolkmedicinaltreewidelydistributedinTaiwan',andtheaerialpartsofBorroniaromosainAustraliangenusBoroniarespectively'.Theirstructureswereelucidatedas4-(l'-geranyl)-2,6-dihydroxyacet1and4-(l'-farnesyl)-2,6-dihydroxyacetophen2bymeansofspectrosco…