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1996 Volume 7 Issue 3
1996, 7(3): 205-206
Abstract:
The cyclizations of (+)-cis-1,2,2-trimethyl-1,3-diaminocyclopentane 1 derived from D-camphor with O-arylthiophosphorochloridates 2 give products,(+)-2,4,3-diazaphospha-bicyclo[3,2,1] octane 3,containing two unequal amounts of diastereoisomers,a pair of which (R=OEt) has been successfully separated by silica gel column chromatography.
The cyclizations of (+)-cis-1,2,2-trimethyl-1,3-diaminocyclopentane 1 derived from D-camphor with O-arylthiophosphorochloridates 2 give products,(+)-2,4,3-diazaphospha-bicyclo[3,2,1] octane 3,containing two unequal amounts of diastereoisomers,a pair of which (R=OEt) has been successfully separated by silica gel column chromatography.
1996, 7(3): 207-210
Abstract:
A novel β-cyclodextrin derivative bearing mono-(6-anilino-β-cyclodextrin) (6-anilino-β-CD) was synthesized by a convenient method with 45% yield,and the host compound was characterized by 1H-NMR,FT-IR spectra and elemental analysis,etc.The spectral titrations have been performed in aqueous solution (pH=7.20) to give the stability constants and thermodynamic parameters for the supramolecular system formation of some amino acids with host compound.
A novel β-cyclodextrin derivative bearing mono-(6-anilino-β-cyclodextrin) (6-anilino-β-CD) was synthesized by a convenient method with 45% yield,and the host compound was characterized by 1H-NMR,FT-IR spectra and elemental analysis,etc.The spectral titrations have been performed in aqueous solution (pH=7.20) to give the stability constants and thermodynamic parameters for the supramolecular system formation of some amino acids with host compound.
1996, 7(3): 211-212
Abstract:
Azacrown ethers with intraannular phenolic groups are readily prepared by the reaction of 1,8-bis(p-tolylsulphonylamino)-3,6-dioxaoctane with 2,6-bis(bromomethyl)-4-R-anisole (R=CH3,Cl,Br) in a two-phase system of aqueous lithium hydroxide-toluene in the presence of Bu4 NI as phase transfer catalyst.
Azacrown ethers with intraannular phenolic groups are readily prepared by the reaction of 1,8-bis(p-tolylsulphonylamino)-3,6-dioxaoctane with 2,6-bis(bromomethyl)-4-R-anisole (R=CH3,Cl,Br) in a two-phase system of aqueous lithium hydroxide-toluene in the presence of Bu4 NI as phase transfer catalyst.
1996, 7(3): 213-216
Abstract:
Two new aryl esters with the aza-15-crown-5 structural unit were synthesized.Their structures have been elucidated with IR,1HNMR,MS and elementary analysts.The determinations of DSC and textures have shown that both compounds possess room-temperature mesomorphic properties.
Two new aryl esters with the aza-15-crown-5 structural unit were synthesized.Their structures have been elucidated with IR,1HNMR,MS and elementary analysts.The determinations of DSC and textures have shown that both compounds possess room-temperature mesomorphic properties.
1996, 7(3): 217-220
Abstract:
Five new unsymmertrical tetradentate macrocycles,incorporating sp2 and sp3 nitrogen as donor sites and with donor group-bearing side arms attached to the sp3 nitrogen atoms,were synthesized by an apropriate method.All of the macrocycles were identified by elemental analysis,IR,1H NMR and MS.
Five new unsymmertrical tetradentate macrocycles,incorporating sp2 and sp3 nitrogen as donor sites and with donor group-bearing side arms attached to the sp3 nitrogen atoms,were synthesized by an apropriate method.All of the macrocycles were identified by elemental analysis,IR,1H NMR and MS.
1996, 7(3): 221-224
Abstract:
tert-Butyl alcohol was carbonylated into iso-valeric esters in 37.0-83.6% yield with 42.4-95.0% selectivity using the Pd(OAc)2-PPh3-p-toluenesulfonic acid catalyst system without any halogen promoter or other extreme conditions.
tert-Butyl alcohol was carbonylated into iso-valeric esters in 37.0-83.6% yield with 42.4-95.0% selectivity using the Pd(OAc)2-PPh3-p-toluenesulfonic acid catalyst system without any halogen promoter or other extreme conditions.
1996, 7(3): 225-228
Abstract:
A bioactive constituent (E)-1,5-bis(3',4'-dimethoxyphenyl) pent-4-en-1-yne from the Hypoxis rooperi and its homologue,were conveniently synthesized through the copper (Ⅰ) catalyed coupling reaction of terminal alkyne under the solid-liquid phase transfer condition.
A bioactive constituent (E)-1,5-bis(3',4'-dimethoxyphenyl) pent-4-en-1-yne from the Hypoxis rooperi and its homologue,were conveniently synthesized through the copper (Ⅰ) catalyed coupling reaction of terminal alkyne under the solid-liquid phase transfer condition.
1996, 7(3): 229-232
Abstract:
The oxidative methylaion of toluene with methane to ethylbenzene and styrene proceeded over basic Y type zeolite catalyst at 1023K.KY was prepared from NaY raw powder by exchange with O.SM KOH aqueous solution at 363K.Loaded KY were prepared by impregnating aqueous solutions of LiNO3 and CsNO3 onto KY zeolite.Only KY zeolite showed very low C8-yield and selectivity.Addition of alkali-metal oxides to the KY zeolite increased greatly the catalytic activity.The Cs2O(6wt% Cs2O)/KY catalyst gave the highest C8 yield of 32.2% with selectivity of 60.9%.
The oxidative methylaion of toluene with methane to ethylbenzene and styrene proceeded over basic Y type zeolite catalyst at 1023K.KY was prepared from NaY raw powder by exchange with O.SM KOH aqueous solution at 363K.Loaded KY were prepared by impregnating aqueous solutions of LiNO3 and CsNO3 onto KY zeolite.Only KY zeolite showed very low C8-yield and selectivity.Addition of alkali-metal oxides to the KY zeolite increased greatly the catalytic activity.The Cs2O(6wt% Cs2O)/KY catalyst gave the highest C8 yield of 32.2% with selectivity of 60.9%.
1996, 7(3): 233-236
Abstract:
The synthesis with high yield of a series of 4-acyl anisole was performed through the Friedel-Crafts reaction of anisole with alkanoic or substituted benzoic acids in the presence of an ultrastable Y zeolite (USY) catalyst.
The synthesis with high yield of a series of 4-acyl anisole was performed through the Friedel-Crafts reaction of anisole with alkanoic or substituted benzoic acids in the presence of an ultrastable Y zeolite (USY) catalyst.
1996, 7(3): 237-240
Abstract:
Further chemical study on the fresh roots of Stellaria delavayi led to the isolation of another new cyclopeptide,namely stelladelin D.On the basis of spectroscopic analyses and chemical methods,its structure was assigned as cyclo(Gly-Val-Pro-Ser-Pro-Tyr-Phe-Pro-Ala-Ala-Ile).
Further chemical study on the fresh roots of Stellaria delavayi led to the isolation of another new cyclopeptide,namely stelladelin D.On the basis of spectroscopic analyses and chemical methods,its structure was assigned as cyclo(Gly-Val-Pro-Ser-Pro-Tyr-Phe-Pro-Ala-Ala-Ile).
1996, 7(3): 241-244
Abstract:
Two new polyoxygenated cyclohexenes,named uvarigranol E(Ⅰ) and F(Ⅶ),were isolated from the rhizome of Uvaria grandiflora.On the basis of spectral analysis and chemical derivatizations, including preparation of Mosher esters,the structures of Ⅰ and Ⅶ were established as 1R-acetoxymethyl-1,2S-dihydroxy-3R,6S-dibenzoyloxy-cyclohex-4-ene and 1R-hydroxymethyl-1,2S-dihydroxy-3R,6S-dibenzoyloxy-cyclohex-4-ene.
Two new polyoxygenated cyclohexenes,named uvarigranol E(Ⅰ) and F(Ⅶ),were isolated from the rhizome of Uvaria grandiflora.On the basis of spectral analysis and chemical derivatizations, including preparation of Mosher esters,the structures of Ⅰ and Ⅶ were established as 1R-acetoxymethyl-1,2S-dihydroxy-3R,6S-dibenzoyloxy-cyclohex-4-ene and 1R-hydroxymethyl-1,2S-dihydroxy-3R,6S-dibenzoyloxy-cyclohex-4-ene.
1996, 7(3): 245-248
Abstract:
Based on the models of dopamine receptors and tetrahydroprotoberberine complexes,we carried out semiempirical quantum chemical calculations on the active sites of receptors and Iigands.The results showed that the frontier molecular orbitals of ligand and receptor just matched each other,which suggested that ligand and receptor might form charge-transfer interaction.
Based on the models of dopamine receptors and tetrahydroprotoberberine complexes,we carried out semiempirical quantum chemical calculations on the active sites of receptors and Iigands.The results showed that the frontier molecular orbitals of ligand and receptor just matched each other,which suggested that ligand and receptor might form charge-transfer interaction.
1996, 7(3): 249-252
Abstract:
Using comparative molecular field analysis approach,the interaction of 17 tetrahydroprotoberberines to D1 receptor and 15 ones to D2 receptor have been studied by 3D-QSAR,respectively.The results indicated that the interactions of THPBs with dopamine receptors were primarily electrostatic interactions,with more positive charge in ligand and more negative in receptor.
Using comparative molecular field analysis approach,the interaction of 17 tetrahydroprotoberberines to D1 receptor and 15 ones to D2 receptor have been studied by 3D-QSAR,respectively.The results indicated that the interactions of THPBs with dopamine receptors were primarily electrostatic interactions,with more positive charge in ligand and more negative in receptor.
1996, 7(3): 253-256
Abstract:
On the basis of conformational search for ten huperzine A analogs according to the structure of AChE active site with our approach BCSPL,we performed a 3D-QSAR analysis for these compounds using molecular modeling and CoMFA method.The calculation results can be used to explain the relationship between the structure properties and the activities.
On the basis of conformational search for ten huperzine A analogs according to the structure of AChE active site with our approach BCSPL,we performed a 3D-QSAR analysis for these compounds using molecular modeling and CoMFA method.The calculation results can be used to explain the relationship between the structure properties and the activities.
1996, 7(3): 257-258
Abstract:
Five samples of SiMCM-41,AlSiMCM-41,FeSiMCM-41,LaSiMCM-41 and AlLaSiMCM-41 were synthesized and their good thermal stability was proved by TG/DTA and XRD.All the samples were thermal stable up to about 1150-1160 K.LaSiMCM-41 and FeSiMCM-41 showed better hydrothermal stability.
Five samples of SiMCM-41,AlSiMCM-41,FeSiMCM-41,LaSiMCM-41 and AlLaSiMCM-41 were synthesized and their good thermal stability was proved by TG/DTA and XRD.All the samples were thermal stable up to about 1150-1160 K.LaSiMCM-41 and FeSiMCM-41 showed better hydrothermal stability.
1996, 7(3): 259-262
Abstract:
MCM-41 zeolite and Iron (Ⅱ)-Phen/MCM-41 zeolite have been prepared and characterized by XRD,IR,NH3-TPD,BET and UV-Vis.The Iron(Ⅱ)-Phen/MCM-41 zeolite+30% H2O2 system is capable for catalyzing hydroxylation of phenol.
MCM-41 zeolite and Iron (Ⅱ)-Phen/MCM-41 zeolite have been prepared and characterized by XRD,IR,NH3-TPD,BET and UV-Vis.The Iron(Ⅱ)-Phen/MCM-41 zeolite+30% H2O2 system is capable for catalyzing hydroxylation of phenol.
1996, 7(3): 263-264
Abstract:
The crystal structure of the ternary complex [Cu(L)(2,2'-bipy)H2O]·2H2O (L=phenylmalonate) has been determined by X-ray diffraction methods.The copper(Ⅱ) center in five-coordinate square-pyramidal structure.It is of interest in this structure that the complex involves a metal ion bridge ligand-ligand aromatic ring stacking interaction.
The crystal structure of the ternary complex [Cu(L)(2,2'-bipy)H2O]·2H2O (L=phenylmalonate) has been determined by X-ray diffraction methods.The copper(Ⅱ) center in five-coordinate square-pyramidal structure.It is of interest in this structure that the complex involves a metal ion bridge ligand-ligand aromatic ring stacking interaction.
1996, 7(3): 265-266
Abstract:
The chemical speciations of Pb2+ in the aqueous solution can be calculated using a Feedback Neural Network.The effects of CO32-,random error and temperature on the simulation results were discussed.The results showed that CO32- in aqueous solution is an important affecting factor within 4 < pH < 9.
The chemical speciations of Pb2+ in the aqueous solution can be calculated using a Feedback Neural Network.The effects of CO32-,random error and temperature on the simulation results were discussed.The results showed that CO32- in aqueous solution is an important affecting factor within 4 < pH < 9.
1996, 7(3): 267-268
Abstract:
In this paper boron was determined with on-line separation and preconcentration technique by microwave plasma torch atomic emission spectrometry (MPT-AES).Boron in steel samples was determined with satisfactory results.
In this paper boron was determined with on-line separation and preconcentration technique by microwave plasma torch atomic emission spectrometry (MPT-AES).Boron in steel samples was determined with satisfactory results.
1996, 7(3): 269-270
Abstract:
In this letter the catalytic properties of zirconia in CO hydrogenation are presented.The catalylsts were prepared under different conditions.Some of them have good activity and selectivity for olefins,especially for isobutcne.The catalysts were characterized by EPR technique.The results showed that all good catalysts give an EPR signal at g=1.974 which canbe assigned to Zr3+ on the surface of ZrO2.The probable active center of ZrO2 catalyst was suggested.
In this letter the catalytic properties of zirconia in CO hydrogenation are presented.The catalylsts were prepared under different conditions.Some of them have good activity and selectivity for olefins,especially for isobutcne.The catalysts were characterized by EPR technique.The results showed that all good catalysts give an EPR signal at g=1.974 which canbe assigned to Zr3+ on the surface of ZrO2.The probable active center of ZrO2 catalyst was suggested.
1996, 7(3): 271-272
Abstract:
The FTIR spectra of the ternary Li2S-B2O3-LiBr oxysulfide glasses have been recorded.Assignment of main bands obtained in the spectra indicates the formation of so-called semithio-tetraborate groups and transformation to semi-thio-diborate groups with increasing Li2S content.
The FTIR spectra of the ternary Li2S-B2O3-LiBr oxysulfide glasses have been recorded.Assignment of main bands obtained in the spectra indicates the formation of so-called semithio-tetraborate groups and transformation to semi-thio-diborate groups with increasing Li2S content.
1996, 7(3): 273-274
Abstract:
The mixed multilayers of xEu(TTA)3Phen+(1-x)Gd(TTA)3Phen (x=0.5%,0.3% or 0.1%,in molar percentage)/Arachidic Acid=1/1 (in molar ratio) were fabricated by LB technique.The columinescence effect of rare earth complexes was observed and studied by detecting the fluorescence emission intensity of europium in the LB films.
The mixed multilayers of xEu(TTA)3Phen+(1-x)Gd(TTA)3Phen (x=0.5%,0.3% or 0.1%,in molar percentage)/Arachidic Acid=1/1 (in molar ratio) were fabricated by LB technique.The columinescence effect of rare earth complexes was observed and studied by detecting the fluorescence emission intensity of europium in the LB films.
1996, 7(3): 275-278
Abstract:
Three new azo-reagents having different numbers of hydroxy groups ortho to the azo-group,i.e., 2-(2',4',6'-trihydroxyphenylazo)-, 2-(2',4'-dihydroxyphenylazo)-and 2-(4'-hydroxyphenylazo)benzenearsonic acid,were synthesized.Through comparative studies on the reactions of the three reagents with various metal ions,especially with iron(Ⅲ),it was found that not only selectivities but also sensitivities of azo-reagents can be improved by utilizing rationally the steric effect of groups ortho to the azo-group.The reasons for the improvements were discussed.
Three new azo-reagents having different numbers of hydroxy groups ortho to the azo-group,i.e., 2-(2',4',6'-trihydroxyphenylazo)-, 2-(2',4'-dihydroxyphenylazo)-and 2-(4'-hydroxyphenylazo)benzenearsonic acid,were synthesized.Through comparative studies on the reactions of the three reagents with various metal ions,especially with iron(Ⅲ),it was found that not only selectivities but also sensitivities of azo-reagents can be improved by utilizing rationally the steric effect of groups ortho to the azo-group.The reasons for the improvements were discussed.
1996, 7(3): 279-282
Abstract:
From the aerial parts of Clerodendrum indicum,a novel spiro-compound,named cleroindicin A,was isolated and identified as 7-hydroxy-1-oxy spiro[3,5] nonane,on the basis of chemical convertion and 2D NMR techniques.
From the aerial parts of Clerodendrum indicum,a novel spiro-compound,named cleroindicin A,was isolated and identified as 7-hydroxy-1-oxy spiro[3,5] nonane,on the basis of chemical convertion and 2D NMR techniques.
1996, 7(3): 283-284
Abstract:
The active intermediates "substituted aniline radicals" were detected by ESR method during the reduction of substituted nitroarenes in the presence of methylviologen (MV2+) as electron-transfer catalyst (ETC).
The active intermediates "substituted aniline radicals" were detected by ESR method during the reduction of substituted nitroarenes in the presence of methylviologen (MV2+) as electron-transfer catalyst (ETC).
1996, 7(3): 285-288
Abstract:
The stability constants (Ka) for inclusion complexes of β-cyclodextrin (β-CD) with substituted benzenes were predicted by the Artificial Neural Networks (ANN).The stability constants obtained by ANN from the substituent molar refraction (Rmx),hydrophobic coefficient (πx) and Hammett constant (σx) are very close to those determined experimentally.It suggested that the van der Waals force and hydrophobic interactions play important roles in CD inclusion complex formation.
The stability constants (Ka) for inclusion complexes of β-cyclodextrin (β-CD) with substituted benzenes were predicted by the Artificial Neural Networks (ANN).The stability constants obtained by ANN from the substituent molar refraction (Rmx),hydrophobic coefficient (πx) and Hammett constant (σx) are very close to those determined experimentally.It suggested that the van der Waals force and hydrophobic interactions play important roles in CD inclusion complex formation.
1996, 7(3): 289-292
Abstract:
Four kinds of phenol-formaldehyde resins containing benzo-15-crown-5 ether were synthesized for lithium isotope separation.The adsorption capacity and isotope effect of Li+ in these resins have been investigated.Single separation factors 1.023~1.056 were obtained with batch method from isotope ratios,6Li+ and 7Li+ were enriched in the resin phase and liquid phase,respectively.
Four kinds of phenol-formaldehyde resins containing benzo-15-crown-5 ether were synthesized for lithium isotope separation.The adsorption capacity and isotope effect of Li+ in these resins have been investigated.Single separation factors 1.023~1.056 were obtained with batch method from isotope ratios,6Li+ and 7Li+ were enriched in the resin phase and liquid phase,respectively.
1996, 7(3): 293-296
Abstract:
The geometry and the energy of conformers of PnHn+2(n=2-9) have been studied with PM3 method.It is concluded that gauche interaction between adjacent lone electron pairs and gauche interaction between P-H bond with adjacent P-P bond are important for predicting the stable conformer of open-chain phosphoanes.
The geometry and the energy of conformers of PnHn+2(n=2-9) have been studied with PM3 method.It is concluded that gauche interaction between adjacent lone electron pairs and gauche interaction between P-H bond with adjacent P-P bond are important for predicting the stable conformer of open-chain phosphoanes.
1996, 7(3): 297-298
Abstract:
In this paper,slow pelleting flocculation of polymer latex consisting of butadiene,styrene and methyl methacrylate(MBS) were investigated,using aqueous H2SO4 as coagulant.It is found that spherical particles with uniform particle size and high bulk density were produced in the narrow range of pH.In order to obtain good particle morphology,well-distributed concentration,temperature and shear field in the coagulating system were required.
In this paper,slow pelleting flocculation of polymer latex consisting of butadiene,styrene and methyl methacrylate(MBS) were investigated,using aqueous H2SO4 as coagulant.It is found that spherical particles with uniform particle size and high bulk density were produced in the narrow range of pH.In order to obtain good particle morphology,well-distributed concentration,temperature and shear field in the coagulating system were required.
