One pot synthesis of bis-silicon-bridged stilbene derivatives

Bis-silicon-bridged stilbene derivatives were synthesized in a modified procedure that combined the preparation of bis[2- (silyl)phenyl]acetylene and its intramolecular reductive cyclization in one pot.The results indicated that the one pot approach produced target products in a comparable yield to that of the two-step method reported previously.     

Rapid synthesis of kahweofuran and its derivatives, the coffee aroma components

Kahweofuran, as an impact flavor component of roasted coffee and possesses the 6-methyl-2,3-dihydrothieno[2,3-c]furan structure, was rapidly synthesized from 2-acetyl-3-hydroxymethylthiophene by the formal reductive cyclization using the Wilkinson’s catalyst. Similarly, the syntheses of the 4-methyl, 6-ethyl and 4,6-dimethyl derivatives were also achieved in favorable yields.     

Facile synthesis and antitumor activity of novel 2-trifluoromethylthieno[2,3-d]pyrimidine derivatives

A series of novel 2-trifluoromethylthieno[2,3-d]pyrimidine derivatives were synthesized by a facile three-step procedure that afforded advantages of mild reaction conditions, simple protocol and good yields. The structures of the final compounds were confirmed by 1R, NMR, El-MS, elemental analysis, and X-ray diffraction. Preliminary bioassay results showed that some of the analogs exhibit excellent antitumor activity against MCF-7 and HepG2, especially compounds 3a, 3b, 3e and 3h exhibited higher activity than the positive control gefitinib.     

Convenient synthesis of 4-tert-butyl 2-ethyl 3-amino-1-benzyl-5-dialkylamino-1H-pyrrole-2,4-dicarboxylate derivatives

Optimization details and limitations of a novel synthetic method of 4-tert-butyl 2-ethyl 3-amino-1-benzyl-5-dialkylamino-1H-pyrrole-2,4-dicarboxylate derivatives are herein disclosed. This synthesis consists of four steps that include a highly selective cyclization, and can be carried out from starting materials to target compounds without column chromatography purification. The high selectivity is controlled by lithium coordination and steric hindrance caused by tert-butyl ester.     

A convenient one-pot synthesis of 4-, 6-, and 7-azaindoles from aminopyridines

A one-pot synthesis of a variety of substituted 4-, 6-, and 7-azaindoles from commercially available aminopyridines in moderate to good yields is described.     

N8-芳基取代4-氨基-6-氯-7(8H)-蝶啶酮的合成

通过N4-芳基取代4,5,6-三氨基嘧啶与草酸二水合物环合, 得到N8-芳基取代4-氨基-5,8二氢-6,7-蝶啶二酮, 再经氯代, 得到新型N8-芳基取代4-氨基-6-氯-7(8H)-蝶啶酮, 用红外光谱、核磁共振氢谱、核磁共振碳谱、质谱和元素分析确证了其结构. 用X-ray单晶衍射测定了4-氨基-6-氯-8-对甲苯基-7(8H)-蝶啶酮(3a)的晶体结构, 证明了环合反应的区域选择性.     

Electroorganic synthesis of 6-aminonicotinic acid from 2-amino-5-chloropyridine

A synthesis of 6-aminonicotinic acid by electrochemical hydrogenation of 5-chloro-2-nitropyridine and electrochemical carboxylation of 2-amino-5-chloropyridine at a cathode surface in the presence of sulphuric acid and carbon dioxide in a dimethylformamide (DMF) solution at an apparent current density of 10 mA/cm² using an undivided cell with good yields is reported.     

Electrochemical synthesis of 6-amino-5-(3,4-dihydroxyphenyl) pyrimidine

Electrochemical oxidation of several catechols is studied in the presence of 4(6)-aminouracil (3a) and 6-amino-1,3-dimethyl uracil (3b) as nucleophiles in aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results reveal that quinones derived from catechols participate in Michael additions with 3a and 3b to give the corresponding catecholamine derivatives via an electron transfer followed by chemical reaction (EC) mechanistic pathway in good yields and purities.     

6-氨基-3-取代吲哚的合成和生物活性研究

6-氨基-3-取代吲哚及其衍生物是一种重要的医药和有机化工中间体,不仅能合成一些具有生理活性和药理活性的化合物,如:合成一些具有药物活性的色胺类化合物及其衍生物[1,2];合成一些植物生长调节剂,如吲哚-3-乙腈和吲哚-3-乙酸类化合物[3];合成一些具有生物活性的天然化合物Drag     

Facile Alternative Synthesis of 1-Alkyl-5-alkylamino-6-phenethyluracils

A short alternative synthesis of 1-alkyl-5-alkylamino-6-phenethyluracil is described in 47% overall yield of 1a via five steps starting from commercially available 6-methyluracil.     

Practical enantioselective synthesis of (3S, 4R)-3-hydroxypiperidine-4-carboxylic acid

A practical enantioselective synthesis of (3S, 4R)-3-hydroxypiperidine-4-carboxylic acid was accomplished via an unconventional Evans anti-aldol reaction followed by a one-pot azide reduction/reductive cyclization.     

A Facile and Highly Stereoselective Reductive Debromination of Anhydro-6- (R)-Hydroxyethyl- 6-Bromopenicillin

Reductive debromination of anhydro-6-(R)-hydroxyethyl-6-bromopenicillin 7 by zinc in ammonium acetate gave 9 in 81% yield with high stereoselectivity of 6-(α):6-(β)=13:1.     

Facile synthesis of 5, 6, 7, 8-tetrahydropyrimido [4, 5-b]-quinoline derivatives

2-Amino-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile (3) was synthesized by treating cyclohexanone (1) with 2-benzylidenemalononitrile (2) in the presence of ammonium acetate. The reactivity of compound 3 towards dimethylformamide dimethyl acetal (DMF-DMA), carbon disulfide, urea, thiourea, formamide, formic acid, acetyl chloride and isothiocyanate were studied. In addition, the antimicrobial activity of some selected derivatives is reported.     

苯并卟啉羟基和醚类衍生物的简便合成

以原卟啉IX二甲酯(1)为起始原料,简便地合成了四种位置异构体苯并卟啉羟基及醚类衍生物:3-甲氧乙基苯并卟啉衍生物16,3-羟乙基苯并卟啉衍生物17,8-甲氧乙基苯并卟啉衍生物20和8-羟乙基苯并卟啉衍生物21。     

Solid-phase synthesis of quinoxaline derivatives using 6-amino-2,3-dichloroquinoxaline loaded on AMEBA resin

The solid-phase synthesis of quinoxaline derivatives 1 was accomplished through successive introduction of building blocks such as amines, methoxide, acid chlorides, and isocyanates into 6-amino-2,3-dichloroquinoxaline 2 loaded on AMEBA resin 3. The method made it possible to obtain the compound 1 in 63-100% purities and 36-89% isolated yields.     

Acrosin structure-based design,synthesis and biological activities of 7-azaindol derivatives as new acrosin inhibitors

A series of 7-azaindol derivatives were designed based on the homologous 3D model of human acrosin.These compounds were synthesized and evaluated for their human acrosin inhibitory activities in vitro.Compounds 7a,7i,7j,7k and 7n showed highly inhibitory activity against human acrosin.The three-dimensional structure-activity relationship was investigated through a CoMFA model,which provided valuable information to further study of potential human acrosin inhibitors.     

强韧抗溶胀水凝胶的简单构筑及性能

以聚乙烯醇(PVA)和壳聚糖(CS)为原料, 采用循环冻融法制备了前驱体水凝胶(PVA-CS), 并经过浸泡氯化钠溶液和透析后处理构筑了强韧抗溶胀复合水凝胶(PVA-CS-6.16-30). 采用扫描电子显微镜(SEM)、 傅里叶变换红外光谱仪(FTIR)、 X射线衍射分析仪(XRD)、 差示扫描量热分析仪(DSC)及流变仪表征了两种水凝胶的微观结构, 采用拉力机测试了其机械性能. 结果表明: 由于结晶微区、 氢键及链缠结等协同交联作用, PVA-CS-6.16-30具备高效能量耗散机制. 与前驱体PVA-CS相比, PVA-CS-6.16-30的交联密度由7.69×10^?4 mol/cm³增加至9.97×10^?4 mol/cm³, 自由水含量由62.8%降低至52.6%, 网络尺寸由6.11 nm降低至5.21 nm, 凝胶分数由58.6%增加至86.8%, PVA结晶度由14.8%增加至17.2%, 其抗拉强度、 断裂伸长率、 韧性及抗压强度分别为2.9 MPa, 229%, 3.3 MJ/m³和7.6 MPa. 此外, 该复合水凝胶还具有优异的耐溶胀与抗蠕变性能. 在37 ℃的PBS缓冲溶液中浸泡7 d后, 其抗拉和抗压强度分别高达2.8和7.5 MPa, 优于常见水凝胶. 商品化的原料、 简单的构筑方法及优异的综合性能有望推动水凝胶在组织工程和生物医疗领域的应用.     

A Facile and Highly Stereoselective Reductive Dcbromination of AnhydrO-6- (R)-Hydroxyethyl- 6-Bromopenicillin

Thetitlecompound,4-acetoxyazetidinone5',hasbeenwidelyusedasanimportantintermediateforpenem,carbapenemandtrinemsynthesisZa~Zfandseveralapproachesto5havebeenreported3a~3c.Thesemisyntheticapproachof4-acetoxyazetidinone5frompenicillinIreportedbyDiNinnoetal.Zbisausefulone,thedebrominationofmethyl6-bromo-6-l(R)-Ihydroxy-ethyllpenicillinate3byzinc-ammoniumacetateaffordedthelabilecompound4.91igmixtureoftransandetsisomers,in92%yieldbutintheformerstepthehydroxyethylationoftheC-6positionofpenicillinat…