151-01-9Relevant academic research and scientific papers
Reaction-induced microphase separation in polybenzoxazine thermosets containing poly(N-vinyl pyrrolidone)-block-polystyrene diblock copolymer
Hu, Di,Zheng, Sixun
, p. 6346 - 6354 (2010)
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.
FOURIER TRANSFORM INFRARED EXTERNAL REFLECTION STUDY OF MOLECULAR ORIENTATION IN SPONTANEOUSLY ADSORBED LAYERS ON LOW-ABSORPTION SUBSTRATES
Mielczarski, J. A.,Yoon, R. H.
, p. 2034 - 2038 (1989)
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.
A synthesis of N-alkyl and N,N-dialkyl O-ethyl thiocarbamates from diethyl dixanthogenate using different oxidants
Milosavljevic, Milutin M.,Sovrlic, Milica,Marinkovic, Aleksandar D.,Milenkovic, Dragan D.
experimental part, p. 749 - 755 (2011/07/08)
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.
Sulphonamido-Substituted Cyclohexyl Sulphones for Treatment of Cancer
-
, (2009/09/07)
Compounds of formula (I) are disclosed for treatment of cancer.
Facile one pot synthesis of a range of reversible addition-fragmentation chain transfer (RAFT) agents
Skey, Jared,O'Reilly, Rachel K.
supporting information; experimental part, p. 4183 - 4185 (2009/03/11)
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.
Modulators of LXR
-
, (2008/06/13)
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.
Process for producing dibenzo[b,f]thiepine derivatives
-
, (2008/06/13)
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.
Antifungal sordaridin derivatives
-
, (2008/06/13)
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.
Fluorogenic substrates for β-lactamase and methods of use
-
, (2008/06/13)
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.
