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.     

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.     

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.     

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…     

Synthesis of a Pair of Derivatives of N-Methylpyrrole Polyamide

A pair of derivatives of tetrameric N-methylpyrrole polyamide were synthesized in order to develop a new method for the study of interaction of the polyamide derivatives with DNA. Indole acetic acid and nicotinic acid were introduced to the polyamide in the synthesized compound, which showed an expected red shift in the UV spectrum. These compounds may function as a potential tool in the detection of the polyamide binding to DNA.     

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…     

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…     

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).     

Synthesis and Antitumor Activity of New Derivatives of Podophyllotoxin

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Stereoselective Reactions of Optically Active Derivatives of α-Methylbenzylaminophosphine

A number of N-(-methylbenzyl) phosphorus amides were synthesized, and their stereochemical properties were studied. Reactions of achiral chlorophosphines with optically active -methylbenzylamine are accompanied by asymmetric induction at the phosphorus atom to give optically active diastereoisomers of N-(-methylbenzyl)aminophosphines, which were isolated as the corresponding borane complexes with 100% optical purity. Stereochemically pure (R,S)-aminophosphines were obtained by decomposition of these complexes via treatment with diethylamine. Their oxidation, sulfurization, and alkylation with methyl iodide afforded optically active aminophosphine derivatives. Hydrolysis of (R,S)-aminophosphines gave optically active tert-butylphenylphosphine oxide and phosphonic acid amides. (R,S)- and (S,S)-Diastereoisomers of N-(-methylbenzyl)phosphinic amides were separated by crystallization and flash chromatography, and their absolute configuration was established. Also, derivatives of bis- and tris(-methylbenzylamino)phosphines were synthesized.     

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…     

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.     

Synthesis of Novel Spin Labeled Daunomycin Derivatives

The anthracycline antibiotics daunomycin 1 is clinically useful antineoplastic agents, with a broad spectrum of activity. However, it is hampered by a number of undesirable side effects, especially serious cardiotoxicity and this stimulated the search for new anthracyclines with improved pharmacological profiles1-3. In our group, nitroxy radicals were first introduced to daunomycin and two spin labeled daunomycin derivatives have been reported recently4. Now we reported other three new spin la…     

Synthesis of Antipyrine Derivatives Derived from Dimedone

Coupling of dimedone with the diazonium salt of 4-aminoantipyrine afforded 2,3-dimethyl-4-[2-（5,5-dimethyl- 2,6-dioxocyclohex-2-ylidend）-hydrazino]-5-oxo-1-phenylpyrazoline （3）. Reaction of 3 with excess phenylhydrazine gave the mixed trishydrazone derivative 4. Treatment of 3 with hydroxylamine produced the bisoxime 5 which upon dehydrative cyclization with acetic anhydride gave the corrsponding tetrahydrobenzo[d][1,2,3]triazole derivative 7. A one-pot synthesis of 7 was done by reacting 3 with hydroxylamine hydrochloride in pyridine, followed by heatment with acetic anhydride.     

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.