- Reaction-induced microphase separation in polybenzoxazine thermosets containing poly(N-vinyl pyrrolidone)-block-polystyrene diblock copolymer
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Poly(N-vinyl pyrrolidone)- block-polystyrene diblock copolymer (PVPy- b-PS) was synthesized via sequential reversible radical-fragmentation transfer polymerization with S-1-phenylethyl O-ethylxanthate as a chain transfer agent. The block copolymer was incorporated into polybenzoxazine to access the nanostructures in the thermosets. The nanostructures in the thermosets were investigated by means of transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). It was found that disordered and/or ordered PS nanophases were formed in the PBa thermosets. It is judged that the formation of nanophases followed the mechanism of reaction-induced microphase separation in terms of the miscibility of the subchains of the diblock copolymer (viz. PVPy and PS) with polybenzoxazine after and before curing reaction.
- Hu, Di,Zheng, Sixun
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- FOURIER TRANSFORM INFRARED EXTERNAL REFLECTION STUDY OF MOLECULAR ORIENTATION IN SPONTANEOUSLY ADSORBED LAYERS ON LOW-ABSORPTION SUBSTRATES
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An infrared reflection absorption spectroscopy (IRAS) technique has been developed to study the structure of spontaneously adsorbed layers of ethyl xanthate (C2H5OCS2(1-) ion) on a semiconductor, cuprous sulfide (chalcocite), from aqueous solutions.Owing to the optical properties of the substrate, positive as well as negative absorption bands are observed in the recorded spectra of the same sample, depending on the angle of incidence and the polarization of the incident radiation.The spectroscopic study was performed on mono- and multilayer coverages of ethyl xanthate. generally good agreement has been obtained between experimental and theoretically calculated absorbance values for a model of the system investigated.The results show that the spectroscopic data obtained with the IRAS method make it possible to determine both the chemical nature and the structure of an adsorbed anisotropic layer at mono- and multilayer coverages on low-absorption substrates.The orientation of the individual molecular groups of adsorbed ethyl xanthate on cuprous sulfide and the chemical nature of the adsorbed species have been determined.The measurement conditions chosen for the IRAS studies of the adsorption layer on low-absorption substrates are also discussed.
- Mielczarski, J. A.,Yoon, R. H.
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Read Online
- A synthesis of N-alkyl and N,N-dialkyl O-ethyl thiocarbamates from diethyl dixanthogenate using different oxidants
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A novel synthesis of N-alkyl and N,N-dialkyl O-ethyl thiocarbamates from diethyl dixanthogenate and primary and secondary amines, using three oxidizing systems, has been developed on the laboratory scale, and the method using sodium hypochlorite has been applied on a semi-industrial scale. The effect of the oxidizing agents, sodium hypochlorite, in-situ-generated peracetic acid, and the manganese(II) acetate/oxygen system on product purity and yield was studied. The results obtained by use of these three methods were compared with those obtained by reaction of sodium ethyl xanthogenacetate and amines, and of sodium ethyl xanthate with amines in the presence of sulfated nickel zeolite catalyst. The reaction mechanism of sodium hypochlorite oxidation has been established on the basis of isolation of reaction intermediates and determination of their structure by use of Fourier-transform infrared, 1H and 13C NMR, and mass spectrometric methods. The suggested sodium hypochlorite and manganese(II) acetate/oxygen systems have many advantages in comparison with commercial and catalytically promoted synthetic methods, because they are new ecologically friendly syntheses. Springer-Verlag 2010.
- Milosavljevic, Milutin M.,Sovrlic, Milica,Marinkovic, Aleksandar D.,Milenkovic, Dragan D.
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experimental part
p. 749 - 755
(2011/07/08)
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- Sulphonamido-Substituted Cyclohexyl Sulphones for Treatment of Cancer
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Compounds of formula (I) are disclosed for treatment of cancer.
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- Facile one pot synthesis of a range of reversible addition-fragmentation chain transfer (RAFT) agents
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The application of a universal synthetic strategy for the high yielding and facile synthesis of a wide range of functional RAFT agents including trithiocarbonates, xanthates and dithiocarbamates is described. The Royal Society of Chemistry.
- Skey, Jared,O'Reilly, Rachel K.
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supporting information; experimental part
p. 4183 - 4185
(2009/03/11)
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- Modulators of LXR
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Compounds of the invention, such as compounds of formula (I): where n, m, A, B, R1, R2, R3, R4 and R5 are defined herein, are useful as modulators of the activity of liver X receptors. Pharmaceutical compositions containing the compounds and methods of using the compounds are also disclosed.
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- Process for producing dibenzo[b,f]thiepine derivatives
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Efficient synthesis of diaryl sulfide derivatives useful as intermediates for pharmaceutical compounds. Provision of a convenient process for producing large quantities of dibenzo[b,f]thiepine derivatives using such intermediates. Halogen-substituted phenyl derivatives of the general formula (1): (where X is a halogen atom and R1-R5is any substituent selected from among hydrogen, a lower alkyl group, a lower cycloalkyl group, an aryl group, a halogen atom, a lower alkoxyl group, an amino group, an N-lower acylamino group, a nitro group, a lower alkylthio group and a carboxyl group) are reacted with disulfide derivatives of the general formula (2): (where R6-R10is any substituent selected from among hydrogen, a lower alkyl group, a lower cycloalkyl group, an aryl group, a halogen atom, a lower alkoxyl group, an amino group, an N-lower acylamino group, a nitro group, a lower alkylthio group and a carboxyl group) in the presence of metal catalysts to form a sulfide bond, thereby producing diaryl sulfide derivatives of the general formula (3): (where R1-R10are the same as defined above) or salts thereof. Pharmaceutical compounds such as dibenzo[b,f]thiepine derivatives are produced from the diaryl sulfide derivatives or salts thereof by known techniques.
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- Antifungal sordaridin derivatives
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Compounds of the formula (I) STR1 and pharmaceutically acceptable salts or metabolically labile derivatives thereof, processes for their preparation, their use as antifungal agents and intermediates for use in their preparation.
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- Fluorogenic substrates for β-lactamase and methods of use
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Fluorogenic substrates of the general formula I STR1 in which one of X and Y is a fluorescent donor moiety and the other is a quencher (which may or may not re-emit); R' is selected from the group consisting of H, lower (i.e., alkyl of 1 to about 5 carbon atoms) and (CH2 OH)n OH, in which n is 0 or an integer from 1 to 5; R is selected from the group consisting of H, physiologically acceptable metal and ammonium cations, --CHR2 OCO(CH2)n CH3, --CHR2 OCOC(CH3)3, acylthiomethyl, acyloxy-alpha-benzyl, delta-butyrolactonyl, methoxycarbonyloxymethyl, phenyl, methylsulphinylmethyl, beta-morpholinoethyl, dialkylaminoethyl, acyloxyalkyl, dialkylaminocarbonyloxymethyl and aliphatic, in which R2 is selected from the group consisting of H and lower alkyl; A is selected from the group consisting of S, O, SO, SO2 and CH2 ; and Z' and Z are linkers for the fluorescent donor and quencher moieties. The substrates are useful in conjunction with β-lactamase as reporter gene in a wide range of assays, for example to determine protein localization or bacterial resistance.
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- Ester syntheses and transesterifiable xanthate reactants therefor
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"Esters" are synthesized by reacting a nucleophile with a propargyl xanthate advantageously having the formula (I): in the presence of at least one acid, Bronsted or otherwise, and at a temperature ranging from 0° to 300° C.; the subject reaction is particularly applicable to a wide variety of chiral organic syntheses.
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- NON-PEPTIDE PEPTIDOMIMETICS
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Compounds are provided which are crossreactive with peptides such as those which bind G-protein-linked receptors, together with preparative and therapeutic methods therefor. The compounds have the general structure: STR1 wherein at least one of R 1, R 2, R. sub.3, R. sub.4, or R 5 comprises a functional group which is chemically similar to that found in the peptide of interest.
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- Deoxy taxols
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Rg is C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-6 cycloalkyl, or a radical of the formula --W--Rx in which W is a bond, C2-6 alkenediyl, or --(CH2)t --, in which t is one to six; and Rx is naphthyl, phenyl, or heteroaryl, and furthermore Rx can be optionally substituted with one to three same or different C1-6 alkyl, C1-6 alkoxy, halogen or --CF3 groups; R2 is --OCOR, H, OH, --OR, --OSO2 R, --OCONRo R, --OCONHR, --OCOO(CH2)t R, or --OCOOR; and R and Ro are independently C1-6 alkyl, C2-6 alkenyl, C3-6 cycloalkyl, C2-6 alkynyl, or phenyl, optionally substituted with one to three same or different C1-6 alkyl, C1-6 alkoxy, halogen or --CF3 groups. Further provided by this invention are pharmaceutical formulations and intermediates for the the preparation of deoxy taxols of formula I. A method of treating mammalian tumors using a compound of formula I is also provided.
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- ANTIPROLIFERATIVE QUINAZOLINES
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Quinazoline compounds which demonstrate antiproliferative activity, such as antitumor activity, processes of preparing these compounds, pharmaceutical compositions containing these compounds, and the use of these compounds. These compounds inhibit the growth and proliferation of the cells of higher organisms and microorganisms,such as bacteria, yeasts and fungi. Preferred quinazoline compounds are capable of inhibiting the enzyme thymidylate synthase. Effects derived from the inhibition of the enzyme thymidylate synthase include those discussed above
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- Methods for the enzymatic synthesis of alpha-sialylated oligosaccharide glycosides
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Disclosed are methods for the enzymatic synthesis of alpha-sialylated oligosaccharide glycosides. Specifically, in the disclosed methods, sialyltransferase is activated to transfer an analogue of sialic acid, employed as its CMP-nucleotide derivative, to an oligosaccharide glycoside. The analogue of sialic acid and the oligosaccharide employed in this method are selected to be compatible with the sialyltransferase employed.
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- Phosphonooxy and carbonate derivatives of taxol
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The present invention is directed to novel taxol derivatives useful as anti-tumor agents. Also provided by this invention is pharmaceutical formulations and methods of treating mammalian tumors with the compounds of this invention.
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- Biocides
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Compounds having a 5 membered, nitrogen containing ring with a thione group adjacent to a nitrogen atom substituted with an OR group have antimicrobial properties. Metal complexes or salts of these compounds also have antimicrobial properties. The compounds, or the metal complexes or salts thereof, can be used as a cutting fluid preservative, a wood preservative, in cooling water applications or as an antimicrobial agent in a paint. Some of the compounds are new. The metal complexes or salts are new.
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- Derivatives of cyclohexane
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New derivatives of cyclohexane in substantially pure form suitable as a pharmaceutical, foodstuff or as a stabilizer.
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- Esters of myo-inositol phosphate
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New derivatives of cyclohexane in substantially pure form suitable as a pharmaceutical, foodstuff or as a stabilizer.
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- PYROTHIOCARBONATES V. SYNTHESIS AND SOME REACTIONS OF S-TRIMETHYLSILYL O-ALKYLDITHIOCARBONATES
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Non-reported S-trimethylsilyl-O-alkyldithiocarbonates (2) are prepared by reaction of O,O-dialkyltrithiodicarbonates with N-methyl-N-trimethylsilylaniline in 87-96percent yield.These air-sensitive liquids which are separated from accompanying phenyl methyl alkylcarbamothioates by fractional distillation.The reaction of 2 with acetyl chloride gives the unsymmetrical dithioanhydrides S-acetyl O-alkyldithiocarbonates in 93-97percent yield.With the less powerfull electrophilic reagent, iodomethane, S-trimethylsilyl O-ethyldithiocarbonate (2a) forms S-methyl O-ethyldithiocarbonate in 30percent yield.When a chloroform solution of 2a is stirred with water the unstable compound O-ethyldithiocarbonic acid is obtained. Key words: Masked O-alkyldithiocarbonic acids; O,O-dialkyltrithiodicarbonates; S-acetyl O-alkyl-dithiocarbonates.
- Palominos, Mario A.,Vega, Juan C.
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p. 319 - 324
(2007/10/02)
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- Deoxyfluoronucleoside process
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There is disclosed a process for synthesizing 2?--fluoro-2?,3?-dideoxyarabinofuranose derivatives of inosine and adenine on a large scale which involves coupling of a fluorosugar derivative and a purine reactant to provide a purine nucleoside intermediate which is then deoxygenated. 6-Chloro or 6-benzamidopurine and 1,3,5-tri-O-benzoyl-2--deoxy-2-fluoroarabinofuranose are used as starting materials.
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- 3,5,6-substituted derivatives of 1,2-O-isopropylidene-α,D-glucofuranose and intermediates for preparing these derivatives
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Derivatives of 1,2-O-isopropylidene-α,D-glucofuranose and intermediates for preparing these derivatives are described. These derivatives are useful for treating animals and mammals with inflammatory and/or autoimmune disorders such as autoimmune deficiency syndrome, psoriasis, atopic dermatitus, rheumatoid arthritis, osteoarthritis, scleroderma and systemic lupus erythematosus.
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- Mercapto-compounds having mucolytic action and a process for their preparation
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A series of new compounds represented by the following general formula (I) wherein R1 = H, SH, R2 = H, SH, R3 = OH, SH, R4 = H, OH, SH, R5 = H, OH, SH, and R4 and R5 taken together represent =O is described. The compounds represented by the general formula (I) possess a mucolytic action.
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- Oxa-fenchyl esters and amides of alpha-L-aspartyl-D-phenylglycine
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Oxa-fenchyl esters and amides of alpha-L-aspartyl-D-phenylglycine are disclosed to be useful as high intensity sweeteners. These compounds can be used to sweeten a variety of foods, beverages and other oral products.
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- Xanthates and antiviral use thereof
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Novel antiviral xanthate compounds, a process for their production, pharmaceutical compositions containing said xanthate compounds, and a method of combating viruses therewith, are disclosed.
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- Encapsulation by entrapment
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Chemical biological agents to be encapsulated are dissolved or dispersed in an aqueous solution of polyhydroxy polymer xanthate. Simultaneous addition of a strong acid and a coupling agent to the solution insolubilizes the polyhydroxy polymer without degrading the xanthate moiety, thereby entrapping the agents in a protective matrix. Encapsulation of biologically active compositions provides a shield against hostile environments, improves safety in handling, and slows the release of such compounds to the surrounding medium. Highly volatile liquids are protected against losses by evaporation. Encapsulation also provides protection against decomposition from exposure to ultraviolet light.
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- Encapsulation by entrapment
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Water-soluble and water-insoluble solid and liquid core materials are encapsulated by the same method. Core materials are simply entrapped in a matrix of water-insoluble polyhydroxy polymers which are insolubilized from their corresponding water-soluble xanthates in the presence of the core materials. Encapsulation of biologically active compositions provides a shield against hostile environments, improves safety in handling, and slows the release of such compounds to the surrounding medium. Highly volatile liquids are protected against losses by evaporation. Encapsulation also provides protection against decomposition from exposure to ultraviolet light.
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- Xanthogen disulphides with functional groups
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This invention relates to xanthogen disulphides of the formula STR1 in which R is the same or different and denotes the following groups: STR2 wherein X = H, alkyl, aryl, aralkyl or halogen n = 1 to 20, A process for preparing them, a process for polymerizing dienes and α-olefines in the presence of these particular xanthogen disulphides and to vulcanizable rubber mixtures consisting of an uncross-linked benzene soluble chloroprene homopolymer or copolymer which is prepared in the presence of said xanthogen disulphides.
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