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2003 Volume 14 Issue 4
2003, 14(4): 331-332
Abstract:
Three novel poly(ether imide)s were synthesized by one-step solution polymerization from 2-(3, 4-dicarboxyl-N-phenyl)-4-(3', 4'-dicarboxyl-phenoxyl-4-(2-methyl)-phenyl)-2, 3-phthal-azin-1-one dianhydride and three amines, and characterized. The polymers show good solubility and thermal properties.
Three novel poly(ether imide)s were synthesized by one-step solution polymerization from 2-(3, 4-dicarboxyl-N-phenyl)-4-(3', 4'-dicarboxyl-phenoxyl-4-(2-methyl)-phenyl)-2, 3-phthal-azin-1-one dianhydride and three amines, and characterized. The polymers show good solubility and thermal properties.
2003, 14(4): 333-334
Abstract:
A new rapid synthetic method is described for synthesis of α,α'-dibenzylidene-cycloalkanones by the reaction of acetals and cycloalkanones without solvent using BF3·Et2O as catalyst under microwave irradiation.
A new rapid synthetic method is described for synthesis of α,α'-dibenzylidene-cycloalkanones by the reaction of acetals and cycloalkanones without solvent using BF3·Et2O as catalyst under microwave irradiation.
2003, 14(4): 335-337
Abstract:
Polystyrene-supported benzyl selenide has been prepared. This novel reagent was treated with LDA to produce a selenium stabilized carbanion, which reacted with alkyl halide, followed by selenoxide syn-elimination, to give substituted olefins stereospecificly.
Polystyrene-supported benzyl selenide has been prepared. This novel reagent was treated with LDA to produce a selenium stabilized carbanion, which reacted with alkyl halide, followed by selenoxide syn-elimination, to give substituted olefins stereospecificly.
2003, 14(4): 338-340
Abstract:
Synthesis of the optically active metabolite of clausenamide CM2 (3, 5-dihydroxy-5-(α-hydroxylbenzyl)-1-methyl-4-benzylpyrrolidin-2-one) from 3-O-acetyl-clausenamide was described.
Synthesis of the optically active metabolite of clausenamide CM2 (3, 5-dihydroxy-5-(α-hydroxylbenzyl)-1-methyl-4-benzylpyrrolidin-2-one) from 3-O-acetyl-clausenamide was described.
2003, 14(4): 341-342
Abstract:
A simple and efficient procedure has been developed for the synthesis of organostannane compounds by one-pot reaction of stannane halides, magnesium turnings and organic halides in the presence of 1, 2-dibromoethane under ultrasound irradiation for the first time.
A simple and efficient procedure has been developed for the synthesis of organostannane compounds by one-pot reaction of stannane halides, magnesium turnings and organic halides in the presence of 1, 2-dibromoethane under ultrasound irradiation for the first time.
2003, 14(4): 343-346
Abstract:
A series of N-phosphoryl branched peptides were synthesized by coupling of various N-phosphoryl amino acids to L-Lysine methyl ester, and their structures were confirmed by 31P NMR, 1H NMR, MS and elemental analysis. The results of cell biological tests indicated that compound 1d and 1e obviously inhibited the growth of both K562 and A2780 cells.
A series of N-phosphoryl branched peptides were synthesized by coupling of various N-phosphoryl amino acids to L-Lysine methyl ester, and their structures were confirmed by 31P NMR, 1H NMR, MS and elemental analysis. The results of cell biological tests indicated that compound 1d and 1e obviously inhibited the growth of both K562 and A2780 cells.
2003, 14(4): 347-350
Abstract:
10-Hydroxy-5-methyl-5, 10-dihydrophenophosphazine 10-oxide (1) was prepared by a new technique of treating 10-methoxy-5,10-dihydrophenophosphazine 10-oxide (2) with an equivalent of NaH in anhydrous DMF, and then at 120℃ for 3~4 h, which not only avoided poisonous and expensive methyl iodide used in literature, but made the consumption of NaH greatly decrease as well. The possible reaction mechanism was also described. The chemical structure of 1 was confirmed by IR, NMR, and mass spectroscopy.
10-Hydroxy-5-methyl-5, 10-dihydrophenophosphazine 10-oxide (1) was prepared by a new technique of treating 10-methoxy-5,10-dihydrophenophosphazine 10-oxide (2) with an equivalent of NaH in anhydrous DMF, and then at 120℃ for 3~4 h, which not only avoided poisonous and expensive methyl iodide used in literature, but made the consumption of NaH greatly decrease as well. The possible reaction mechanism was also described. The chemical structure of 1 was confirmed by IR, NMR, and mass spectroscopy.
2003, 14(4): 351-354
Abstract:
A mixture of hypophosphorous acid (H3PO2) and iodine in acetic acid can cleave the N-alkyl bond in a variety of N-1 substituted pyrimidine derivative in relatively high yields, withoutany damage to the amido bond in the non-nucleosides pyrimidine base skeleton.
A mixture of hypophosphorous acid (H3PO2) and iodine in acetic acid can cleave the N-alkyl bond in a variety of N-1 substituted pyrimidine derivative in relatively high yields, withoutany damage to the amido bond in the non-nucleosides pyrimidine base skeleton.
2003, 14(4): 355-358
Abstract:
The chemoselective addition of aldehydes in aquoues medium was obtained under mild condition using improved Henry reaction.
The chemoselective addition of aldehydes in aquoues medium was obtained under mild condition using improved Henry reaction.
2003, 14(4): 359-360
Abstract:
Nordihydroguaiaretic acid (NDGA) has been synthesized in nine steps from piperonal using Stobbe condensation as the key step with high yield. By this approach, five relative natural products were obtained.
Nordihydroguaiaretic acid (NDGA) has been synthesized in nine steps from piperonal using Stobbe condensation as the key step with high yield. By this approach, five relative natural products were obtained.
2003, 14(4): 361-364
Abstract:
Two spirostanol saponins (gracillin and dioscin) which have the typical sugar moieties were synthesized facilely by a general approach.
Two spirostanol saponins (gracillin and dioscin) which have the typical sugar moieties were synthesized facilely by a general approach.
2003, 14(4): 365-367
Abstract:
An improved method for preparation of 4-methyl-2-phenyl piperazine and its derivatives with higher yield and inexpensive reagents was developed, the products were characterized by 1H-NMR and MS.
An improved method for preparation of 4-methyl-2-phenyl piperazine and its derivatives with higher yield and inexpensive reagents was developed, the products were characterized by 1H-NMR and MS.
2003, 14(4): 368-370
Abstract:
A novel bisupporter bimetal catalyst PVP-PdCl2-SnCl4/MontK10-PEG400, using for dehalogenation of insoluable aromatic halides in aqueous system, has shown high dechlorination activity and selectivity, without any organic solvent or phase transfer catalyst. The conversion of aromatic chlorides can reach 100%. The catalyst is easy to prepare and has good reusability.
A novel bisupporter bimetal catalyst PVP-PdCl2-SnCl4/MontK10-PEG400, using for dehalogenation of insoluable aromatic halides in aqueous system, has shown high dechlorination activity and selectivity, without any organic solvent or phase transfer catalyst. The conversion of aromatic chlorides can reach 100%. The catalyst is easy to prepare and has good reusability.
2003, 14(4): 371-374
Abstract:
The selective brominations of 3, 4-dimethoxytoluene with N-bromosuccinimide were reported. The nuclear and side-chain brominated products were obtained under different reaction conditions. The mechanism was also discussed.
The selective brominations of 3, 4-dimethoxytoluene with N-bromosuccinimide were reported. The nuclear and side-chain brominated products were obtained under different reaction conditions. The mechanism was also discussed.
2003, 14(4): 375-378
Abstract:
Interaction between chiral diols BDPDD, DMBDPD and BINOL with prochiral compounds was examined and some new supramolecular complexes were prepared. It was found that these chiral hosts could include prochiral guests,α,β-unsaturated compounds or piper-azinedione derivatives to give inclusion crystals in different molar ratio. Formations of these supramolecular complexes were characterized by the data of IR and 1H NMR spectra.
Interaction between chiral diols BDPDD, DMBDPD and BINOL with prochiral compounds was examined and some new supramolecular complexes were prepared. It was found that these chiral hosts could include prochiral guests,α,β-unsaturated compounds or piper-azinedione derivatives to give inclusion crystals in different molar ratio. Formations of these supramolecular complexes were characterized by the data of IR and 1H NMR spectra.
2003, 14(4): 379-382
Abstract:
A new furostanoside, aspafilioside D (1) has been isolated from the root of Asparagus filicinus. Its structure was determined by spectral and chemical methods.
A new furostanoside, aspafilioside D (1) has been isolated from the root of Asparagus filicinus. Its structure was determined by spectral and chemical methods.
2003, 14(4): 383-384
Abstract:
A new diterpenoid,15-O-acetylspiraminol(1),was isolated from the aerial parts of Spireae japonica L.f.var.ovalifolia.The structure was charaterized mainly based on spectral analysis.
A new diterpenoid,15-O-acetylspiraminol(1),was isolated from the aerial parts of Spireae japonica L.f.var.ovalifolia.The structure was charaterized mainly based on spectral analysis.
2003, 14(4): 385-388
Abstract:
Dissectol A, a novel monoterpene glycoside was isolated from the methanol part of the 95% EtOH extract of Incarvillea dissecfoliola and its structure was determined by 1D and 2D NMR data.
Dissectol A, a novel monoterpene glycoside was isolated from the methanol part of the 95% EtOH extract of Incarvillea dissecfoliola and its structure was determined by 1D and 2D NMR data.
2003, 14(4): 389-392
Abstract:
Three new cucurbitacins were isolated from the BuOH extract of the rhizomes of Hemsleya lijiangensis. Their structures were elucidated as 23, 24-dihydro cucurbitacin F-16, 25-diacetate (1), 23,24-dihydro cucurbitacin F-16, 25-diacetate-2-O-β-D-glucopyranoside (2), 23, 24-dihydro-cucurbitacin F-16-acetate (3), respectively; by spectral analyses.
Three new cucurbitacins were isolated from the BuOH extract of the rhizomes of Hemsleya lijiangensis. Their structures were elucidated as 23, 24-dihydro cucurbitacin F-16, 25-diacetate (1), 23,24-dihydro cucurbitacin F-16, 25-diacetate-2-O-β-D-glucopyranoside (2), 23, 24-dihydro-cucurbitacin F-16-acetate (3), respectively; by spectral analyses.
2003, 14(4): 393-396
Abstract:
From the aerial part of Laggera alata, a novel eremophilanoid (1) as well as two new eudesmanoids (2-3) were isolated. Their structures were elucidated by 2D-NMR technique and X-ray diffraction studies. The cytotoxic activities of these sesquiterpenes were also investigated.
From the aerial part of Laggera alata, a novel eremophilanoid (1) as well as two new eudesmanoids (2-3) were isolated. Their structures were elucidated by 2D-NMR technique and X-ray diffraction studies. The cytotoxic activities of these sesquiterpenes were also investigated.
2003, 14(4): 397-400
Abstract:
The mechanism of Au (I) extraction has been characterized using 198Au radiometry, thermodynamic equilibrium, Karl-Fischer titration and FT-IR spectroscopy techniques. The results indicate that the extraction follows ionic combination and solvent interaction mechanism. The stoichiometry of the extracted species is 1:1:4:4 for TDMBA+:Au(CN)2-:TBP:H2O. The microstructure model of the extracted complex is a supramolecular structure via hydrogen bonding, ion dipole interaction and ionic combination. The extraction process can be described as micelles in the aqueous phase transfer into the organic phase and reversed micelles or microemulsion (W/O) form in the organic phase.
The mechanism of Au (I) extraction has been characterized using 198Au radiometry, thermodynamic equilibrium, Karl-Fischer titration and FT-IR spectroscopy techniques. The results indicate that the extraction follows ionic combination and solvent interaction mechanism. The stoichiometry of the extracted species is 1:1:4:4 for TDMBA+:Au(CN)2-:TBP:H2O. The microstructure model of the extracted complex is a supramolecular structure via hydrogen bonding, ion dipole interaction and ionic combination. The extraction process can be described as micelles in the aqueous phase transfer into the organic phase and reversed micelles or microemulsion (W/O) form in the organic phase.
2003, 14(4): 401-403
Abstract:
The influence of different alcohol modifiers in mobile phase on the chiral separation of 4'-methoxyl flavanone, 5-methoxyl flavanone and 6-methoxyl flavanone on cellulose tris (3, 5-dimethylphenylcarbamate) (CDMPC) column was studied and the chiral recognition mechanism was discussed. Using hexane-tert-butanol (1.31 mol L-1) as the mobile phase, those three methoxyl flavanones were excellently separated on CDMPC chiral column.
The influence of different alcohol modifiers in mobile phase on the chiral separation of 4'-methoxyl flavanone, 5-methoxyl flavanone and 6-methoxyl flavanone on cellulose tris (3, 5-dimethylphenylcarbamate) (CDMPC) column was studied and the chiral recognition mechanism was discussed. Using hexane-tert-butanol (1.31 mol L-1) as the mobile phase, those three methoxyl flavanones were excellently separated on CDMPC chiral column.
2003, 14(4): 404-406
Abstract:
A new method was developed to decrease the mass limit of detection (LOD) and increase the number of theoretical plates (N) in capillary electrophoresis with amperometric detection. When the single microcylinder electrode, the 10 μm ID capillary with the etched detection end and the in-capillary alignment were used, the mass LOD for phenol was reduced 124 times and N was increased 36 times in comparison with the normal situation.
A new method was developed to decrease the mass limit of detection (LOD) and increase the number of theoretical plates (N) in capillary electrophoresis with amperometric detection. When the single microcylinder electrode, the 10 μm ID capillary with the etched detection end and the in-capillary alignment were used, the mass LOD for phenol was reduced 124 times and N was increased 36 times in comparison with the normal situation.
2003, 14(4): 407-410
Abstract:
Phase behavior and micellization of dextran-graft-poly (N-isopropylacrylamide) (PNIPAAm) polymers in aqueous solution are investigated in this paper using DSC and AFM methods. It is found that with the increase of grafting (G%) of the copolymers the endothermic enthalpy during the phase transition increases significantly and the transition temperature decreases slightly. The phase transition behavior of the copolymers is scanning rate dependent. Micelles are formed whenever the solution temperature is raised above the LCST of the copolymers. It is proposed that by using this thermal responsive property of the copolymers, drugs could be incorporated into the micelles without employing any organic solvent.
Phase behavior and micellization of dextran-graft-poly (N-isopropylacrylamide) (PNIPAAm) polymers in aqueous solution are investigated in this paper using DSC and AFM methods. It is found that with the increase of grafting (G%) of the copolymers the endothermic enthalpy during the phase transition increases significantly and the transition temperature decreases slightly. The phase transition behavior of the copolymers is scanning rate dependent. Micelles are formed whenever the solution temperature is raised above the LCST of the copolymers. It is proposed that by using this thermal responsive property of the copolymers, drugs could be incorporated into the micelles without employing any organic solvent.
2003, 14(4): 411-412
Abstract:
In this paper, the membrane capacitance (Cm), which was obtained from the electro-chemical impedance spectroscopy (EIS) method, was used to characterize the effect of pH value on the self-assembled monolayers (SAMs) of octadecanethiol(18SH) for the first time. The results not only strongly proved that inorganic ions could penetrate the SAMs of 18SH, but also ascertained that SAMs of 18SH were not an absolute of free of ion-penetration. Verifying the existence of pin-holes in the octadecanethiol SAMs was the main contribution of this paper, which coincided with the former conjecture very well.
In this paper, the membrane capacitance (Cm), which was obtained from the electro-chemical impedance spectroscopy (EIS) method, was used to characterize the effect of pH value on the self-assembled monolayers (SAMs) of octadecanethiol(18SH) for the first time. The results not only strongly proved that inorganic ions could penetrate the SAMs of 18SH, but also ascertained that SAMs of 18SH were not an absolute of free of ion-penetration. Verifying the existence of pin-holes in the octadecanethiol SAMs was the main contribution of this paper, which coincided with the former conjecture very well.
2003, 14(4): 413-416
Abstract:
The synthesis, the crystal structure and the reaction of the hetero-binuclear complex[MnRe(CO)6(μ-SH)(μ-SC(H)PPr3i)(PPh3)] are reported. The results of single crystal X-ray structure analysis showed that the fragments Mn(CO)3 and Re(CO)3 were bridged by SH and SC(H)PPr3i. The title complexes can react with BunLi and RX forming complexes MnRe(CO)6(μ-SR)(μ-SC(H)PPr3i)(PPh3) (R=Me, CH2CH=CH2, SnBu3n).
The synthesis, the crystal structure and the reaction of the hetero-binuclear complex[MnRe(CO)6(μ-SH)(μ-SC(H)PPr3i)(PPh3)] are reported. The results of single crystal X-ray structure analysis showed that the fragments Mn(CO)3 and Re(CO)3 were bridged by SH and SC(H)PPr3i. The title complexes can react with BunLi and RX forming complexes MnRe(CO)6(μ-SR)(μ-SC(H)PPr3i)(PPh3) (R=Me, CH2CH=CH2, SnBu3n).
2003, 14(4): 417-418
Abstract:
Poly (vinyl chloride)/Na+-montmorillonite (PVC/MMT) nanocomposites with different MMT contents were prepared via melt blending. Wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) were used to characterize the structures. Effects of MMT content on the mechanical properties were also studied. It is found that PVC molecular chains can intercalate into the gallery of MMT layers during melt blending process, the stiffness and toughness of the composites are improved simultaneously within 0.5~7wt% MMT content, and the transparency and mechanical properties decrease as MMT content further increases.
Poly (vinyl chloride)/Na+-montmorillonite (PVC/MMT) nanocomposites with different MMT contents were prepared via melt blending. Wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) were used to characterize the structures. Effects of MMT content on the mechanical properties were also studied. It is found that PVC molecular chains can intercalate into the gallery of MMT layers during melt blending process, the stiffness and toughness of the composites are improved simultaneously within 0.5~7wt% MMT content, and the transparency and mechanical properties decrease as MMT content further increases.
2003, 14(4): 419-422
Abstract:
The process, that the polycrystalline TiO2 powders were converted into TiO2 nanotubes, was observed with transmission electron microscope. The results obtained indicated that in concentrated NaOH aqueous solution, anisotropic swelling appears on the polycrystalline TiO2 granula at first, and then the nanotubes are formed.
The process, that the polycrystalline TiO2 powders were converted into TiO2 nanotubes, was observed with transmission electron microscope. The results obtained indicated that in concentrated NaOH aqueous solution, anisotropic swelling appears on the polycrystalline TiO2 granula at first, and then the nanotubes are formed.
2003, 14(4): 423-425
Abstract:
CO2 is converted to methanol through an enzymatic approach using formate dehydro-genase (FateDH), formaldehyde dehydrogenase (FaldDH) and alcohol dehydrogenase (ADH) co-encapsulated in silica gel prepared by modified sol-gel process as catalysts, TEOS as precursor, NADH as an electron donor. The highest yield of methanol was up to 92.1% under 37℃, pH7.0 and 0.3Mpa.
CO2 is converted to methanol through an enzymatic approach using formate dehydro-genase (FateDH), formaldehyde dehydrogenase (FaldDH) and alcohol dehydrogenase (ADH) co-encapsulated in silica gel prepared by modified sol-gel process as catalysts, TEOS as precursor, NADH as an electron donor. The highest yield of methanol was up to 92.1% under 37℃, pH7.0 and 0.3Mpa.
2003, 14(4): 425-428
Abstract:
Resol type phenolic resin/silver nanocomposite was prepared by in-situ reduction method, in which the curing of phenolic resin and the formation of silver nano-particles took place simultaneously. The silver ions were reduced completely to silver nanoparticles, which were dispersed homogeneously in the resin matrix with narrow size distribution.
Resol type phenolic resin/silver nanocomposite was prepared by in-situ reduction method, in which the curing of phenolic resin and the formation of silver nano-particles took place simultaneously. The silver ions were reduced completely to silver nanoparticles, which were dispersed homogeneously in the resin matrix with narrow size distribution.
2003, 14(4): 429-432
Abstract:
With sol-gel method, nanometer La-Ti composite oxide was successfully prepared at a low temperature (750~800℃) using polyethylene glycol as dispersant. By means of atomic force microscope, the surface pattern, particle size distribution, and specific surface area were studied. The compound particle surface appears as a smooth sheet, the mean size of the compound is 25.38 nm. On the specific surface, the particle erects at a height of 4.69 nm. The surface area is 58.90 nm2. The La-Ti composite oxide nanocrystal prefers to narrow and even particle size distribution and the homogeneity of surface topography.
With sol-gel method, nanometer La-Ti composite oxide was successfully prepared at a low temperature (750~800℃) using polyethylene glycol as dispersant. By means of atomic force microscope, the surface pattern, particle size distribution, and specific surface area were studied. The compound particle surface appears as a smooth sheet, the mean size of the compound is 25.38 nm. On the specific surface, the particle erects at a height of 4.69 nm. The surface area is 58.90 nm2. The La-Ti composite oxide nanocrystal prefers to narrow and even particle size distribution and the homogeneity of surface topography.
2003, 14(4): 433-436
Abstract:
Electro-oxidation of 3,4,3', 4(-bis(ethylenedithio)-2,2',5,5(-tetrathiafulvalen (abbr. ET) in the presence of allylsulfonate affords a new charge-transfer salt (ET)2(CH2=CH-CH2-SO3)·H2O. The single crystal structure of the title compound is determined to be in orthorhombic crystal system, Pma2 space group. This salt is a semiconductor and its room-temperature conductivity is 0.0489Ω-1·m-1.
Electro-oxidation of 3,4,3', 4(-bis(ethylenedithio)-2,2',5,5(-tetrathiafulvalen (abbr. ET) in the presence of allylsulfonate affords a new charge-transfer salt (ET)2(CH2=CH-CH2-SO3)·H2O. The single crystal structure of the title compound is determined to be in orthorhombic crystal system, Pma2 space group. This salt is a semiconductor and its room-temperature conductivity is 0.0489Ω-1·m-1.
2003, 14(4): 437-440
Abstract:
Indolinonic aminoxyls can effectively scavenge various radicals by directly coupling with them or by imitating superoxide dismutase. To better understand the radical-coupling reactions, DFT method B3LYP/6-31G(d,p) was employed to calculate variations of free energy for the coupling reactions and other physico-chemical parameters. The radical-coupling activity difference between aminoxyls was elucidated to a large extent in terms of electronic properties of substituents.
Indolinonic aminoxyls can effectively scavenge various radicals by directly coupling with them or by imitating superoxide dismutase. To better understand the radical-coupling reactions, DFT method B3LYP/6-31G(d,p) was employed to calculate variations of free energy for the coupling reactions and other physico-chemical parameters. The radical-coupling activity difference between aminoxyls was elucidated to a large extent in terms of electronic properties of substituents.
