Bio-antioxidant of Anthraquinone Derivatives

The Rubiaceae family is well known for containing anthraquinones. More specifically, lapachol and its analogues are known to possess antitumor, antibiotic, antimalarial and antiulceric activities.[1] Several report indicated that some quinones containing OH in its structure were found to have higher bio-activity than quinines lacking the OH group.     

Structure Comparison of Benzothiazepine Derivatives

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Synthesis of New Benzoimidazole Derivatives

The reactions of cryptotanshinone and tanshinone llA with cadaverine and putrescine were investigated. Six new compounds, four with imidazole functional groups and two with oxazole groups, were obtained. The possible reaction mechanism was proposed.     

TD-DFT Study on Pyrazoline Derivatives

1 INTRODUCTION Pyrazoline compounds have been widely used in industry due to their good photoconductivity and high fluorescence quantum productivity[1]. In recent years, pyrazoline derivatives with high vitrification temperature Tg have been found to act as hole trans- fer materials in the electroluminescence device, which has captured the intensive interest of che- mists[2]. But so far, the electron transfer mechanism of these compounds is still unclear[3~7]. Some resear- ches have attr…     

Antiviral Agents – Benzazine Derivatives

Chemistry of Heterocyclic Compounds - The review outlines the results of studies of the antiviral activity of quinoline, quinoxaline, and quinazoline derivatives published over the past 5 years....     

The Chemistry of Hainanensine Derivatives

Hainanensine(1) and its analog 6 were obtained through intramolecular regiospecific cycliza-tion. Reduction of 6 under different conditions gave 7～12. The stereochemistry was established bychemical correlation, spectral analysis and X-ray diffraction.     

Selective Reduction of gem-Dichlorocyclopropane Derivatives

Cyclopropane derivatives frequently occur as subunits of some natural products as wellas intermediates of medicines and pesticides'. We are interested in the synthesis of I chloro-2,2,3,3-tetramethylcyclop during our synthesis of some new compounds inasymmetric catalysis and in combinatorial chemistry. Closs has synthesized thiscompound via the addition of manochlorocarbene to alkene2. Safiev obtained it via theaddition of monochlorocarbene in PTC-supersonic conditions3. More recently,Bagdan…     

Conversion of 3-Carbethoxy-4-methyl Coumarin Derivatives into Several New Annelated Coumarin Derivatives

The reaction of ethyl esters of 4-methyl-2-oxo-2H-l-benzo(naphtho) pyran.3-carboxylic acids (1) with aromatic aldehy-des in the presence of piperidine yielded 4-styryl-3-carboxami-dopiperidyl connmrin derivatives 4. The reaction of hydrazlne hydrate with 1 gave acetophenone hydrozone derivatives 5 and acetophenone azine derivatives 6. The reaction of 1 with prima-ry amines afforded compomlds 7—9. And the treatment of la with Grignard reagents afforded 3-aroyl-4-methyl coumarin derivatives 10.     

Stereoselective Synthesis of 1,6-Dichloro-1,3,5-Hexatriene Derivatives by Mcmurry Coupling of β-Chloroacrylaldehyde Derivatives

A highly stereoselective synthesis of 1,6-dichloro-1,3,5-hexatriene derivatives by McMurry coupling of β-chloroacrylaldehydes have been developed.     

Convenient Solid-phase Synthesis of Benzothiazole Derivatives

Resin-bound cyclic malonic ester 1 reacted with aryl isothiocynate, then was treated with bromine, followed by cleavage from the resin under perchloric acid to give benzothiazoles 4.     

Synthesis of β–Amino Acid Derivatives

In recent years, β-amino acids and their derivatives have attracted considerable attention due to their occurrence in biologically active natural products, such as dolastatins, cyclohexylnorstatine and Taxol. β–Amino acids also find application in the synthesis of β–lactams, piperidines, indolizidines. Moreover, the peptides consisting of β–amino acids, the so-called β–peptides, have been extensively studied recently. Consequently, considerable efforts have been directed to the synthe…     

Synthesis of Novel Ferrocenyl-containing Thiazole Derivatives

Ferrocenes and their derivatives have been used in material chemistry, electrochemistry and in nonlinear optics. Recently, increasing interests have been focused on their biological activity1. Ferrocifen is a ferrocene derivative of tamoxifen, will be sub…     

A Novel Synthesis of Isoxazole Derivatives

Thenitronesareveryimportantinorganicsynthesis.TheyhavebeenwidelyutilizedasintermediatesfromwhichcomPlexheterocyclicornaturalcompoundsanddrugs"'weresynthesisedsuchasisoxazoline3andoxazine4.However,theconversionofnitronetoisoxazolebythermaldecompositionhasnotbeenreported.Inthispaper,wedevelopanewsyntheticmethodofisoxazolesfromheterocyclicnitronesasfollows:wi.-"'rtXfa.H;b.3,4-O-CH2-o-;c.4-CH3O,d.4-Cl;e.2-Brf.2-Cl,g.3,4-coCH3;h.3-ro2;i.4-so2;j.4-CH3Experiment8lAdriedroundbottomflaskundernit…     

Synthesis of New Fluorinated Podophyllotoxin Derivatives

Five fluorinated podophyUotoxin derivatives were synthesized using dimethylamino-sulfurtrifluoride (DAST).     

Two New Benzofuran Derivatives from Ligularia stenocephala

Two new benzofuran derivatives were isolated from the roots ofLigularia stenocephala.Their structures were established by spectroscopic methods and 2D NMR experiments.     

Synthesis of Isoquinoline Derivatives from β-Hydroxyarylethanamides

A simple and efficient protocol for the construction of medicinally important substituted isoquinolines through intramolecular cyclization of β-hydroxyarylethanamides using acetic anhydride and phosphorous pentoxide in dioxane has been described. The chemo- and regioselectivities due to the influence of different catalysts were investigated and optimized for good to excellent yields. All the synthesized compounds have been characterized by NMR and mass spectral analyses.     

Studies on Properties of p-Nitrophenylazo Calixarene Derivatives

Organiccompoundswithsecond ordernonlinearoptical(NLO)propertieshavevariouspotentialinthedevelopmentofmaterialsforapplicationssuchasfrequencydoublingandop ticalswitching .1,2 TraditionalorganicNLOmaterialsareor ganicmoleculesthatcontainelectron donatingandelectron acceptinggroupsconnectedviaaconjugatedπsystem ,i.e .,socalledD π Astructure .Generally ,thesecond ordernon linearhyperpolarizability βofamoleculeincreaseswithin creasinglengthoftheconjugatedπsystemandincreasingstrengthofthedono…     

Two Pyrone Derivatives from Fungus Phellinus Igniarius

Two new pyrone derivatives phelligridins A 1 and B 2 were isolated from the fruit body of Phellinus igniarius. Their structrues were elucidated as 8, 9-dihydroxy-3-methyl- 1H,6H-pyrano[4,3-c][2]benzopyran-l,6-dione and 4-hydroxy-6-(3‘,4‘-dihvdroxystyryl)-3-methoxycarbon-yl-2-pyrone, respectively, by means of spectral methods,including IR, MS, 1D and 2DNMR spectra.     

Synthesis and Crystal Structure of Isosteviol Derivatives

Isosteviol (ent-16-ketobeyeran-19-oic acid, I) is a tetracyclic diterpenoid with a beyerane skeleton obtained by acid hydrolysis of stevioside.1 Several tetracyclic diterpenoids, specially the kaurenes, have important biological activities. Recent studies on the microbial transformation of isosteviol have revealed that it is metabolized by Cunninghamella bainieri, Actinoplanes sp., Mucor recurvatus, and Cunninghamella blackesleeana to yield five new metabolites.2 The hydroxylation pattern of…     

A Facile Synthesis of Indole-based Conjugated Derivatives

A novel synthetic method was developed for the preparation of indole-based conjugated derivatives with satisfied yields. By applying this strategy, a series of new compounds were prepared conveniently. All the obtained new indole derivatives were characterized by spectroscopic analyses, giving satisfactory data corresponding to their expected molecular structures.