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2000 Volume 11 Issue 10
2000, 11(10): 65-866
Abstract:
A series of new type substituted S-fluorouracil derivatives, 1-aryl-5-fluorouracil (4a-4f), were synthesized via diarvliodonium salts and the structure of the title compound was finally confirmed by IR, UV, 1H-NMR, MS and CHN analysis.
A series of new type substituted S-fluorouracil derivatives, 1-aryl-5-fluorouracil (4a-4f), were synthesized via diarvliodonium salts and the structure of the title compound was finally confirmed by IR, UV, 1H-NMR, MS and CHN analysis.
2000, 11(10): 847-848
Abstract:
A novel reduction system is reported here in which the compounds with terminal C-C triple bond and disubstituted C-C triple bond react with NaBH4/Pd(PPh3)4, in a base condition and only terminal C-C triple bond is reduced.
A novel reduction system is reported here in which the compounds with terminal C-C triple bond and disubstituted C-C triple bond react with NaBH4/Pd(PPh3)4, in a base condition and only terminal C-C triple bond is reduced.
2000, 11(10): 849-850
Abstract:
A mild and reliable procedure for the preparation of α-arylpropanoic acids from arylpropanone by Ce(IV) salt oxidative rearrangement is discribed.
A mild and reliable procedure for the preparation of α-arylpropanoic acids from arylpropanone by Ce(IV) salt oxidative rearrangement is discribed.
2000, 11(10): 851-854
Abstract:
In order to accelerate the development of relatively inexpensive antimalarials that are effective against chloroqtrine-resistant strains of Plasmodium falclparum, a methodology for the solid phase synthesis of chalcone (1 3-diphenyl-2-propen-1-one) analogues in reasonably high yields has been developed.
In order to accelerate the development of relatively inexpensive antimalarials that are effective against chloroqtrine-resistant strains of Plasmodium falclparum, a methodology for the solid phase synthesis of chalcone (1 3-diphenyl-2-propen-1-one) analogues in reasonably high yields has been developed.
2000, 11(10): 855-856
Abstract:
A new approach for preparation of various substituted phenylethylamines from the corresponding nitro compounds with iron powder and NH4Cl in 75% aqueous ethanol solution was developed.
A new approach for preparation of various substituted phenylethylamines from the corresponding nitro compounds with iron powder and NH4Cl in 75% aqueous ethanol solution was developed.
2000, 11(10): 857-860
Abstract:
N-Acetyl-p, m or o-nitro-phenylethylamines and (HCHO)n were treated in 60% H2SO4/HOAc, via α-amidoalkylation to give 2-acetyl-mono(5, 6, 7 or 8)-nitro-1,2,3,4-tetrahydroisoquinolines. Additionally, some interesting phenomena were observed when the comparison between 2-acetyl-5, 6, 7 or 8-nitro-1,2,3,4-tetrahydroisoquinolines and 2-alkylsulfonyl-5,6 or 7-vitro-1,2,3,4-tetrahydroisoquinolines was made.
N-Acetyl-p, m or o-nitro-phenylethylamines and (HCHO)n were treated in 60% H2SO4/HOAc, via α-amidoalkylation to give 2-acetyl-mono(5, 6, 7 or 8)-nitro-1,2,3,4-tetrahydroisoquinolines. Additionally, some interesting phenomena were observed when the comparison between 2-acetyl-5, 6, 7 or 8-nitro-1,2,3,4-tetrahydroisoquinolines and 2-alkylsulfonyl-5,6 or 7-vitro-1,2,3,4-tetrahydroisoquinolines was made.
2000, 11(10): 861-862
Abstract:
In this paper, 2-(5-carboxy-1,3,4-triazolylazo)-5-diethylamino aniline(CTZAN) was prepared, the protonation behaviour of this reagent is reported. Its structure was identitied.
In this paper, 2-(5-carboxy-1,3,4-triazolylazo)-5-diethylamino aniline(CTZAN) was prepared, the protonation behaviour of this reagent is reported. Its structure was identitied.
2000, 11(10): 863-864
Abstract:
The sniro-calix[4]larenes 3a-b can be synthesized conveniently by the reaction of p-tert-butylcalix[4]arene (la) or calix[4]arene (1b) with pentaerythritol tetrakis(2-chloroacetate) (2).
The sniro-calix[4]larenes 3a-b can be synthesized conveniently by the reaction of p-tert-butylcalix[4]arene (la) or calix[4]arene (1b) with pentaerythritol tetrakis(2-chloroacetate) (2).
2000, 11(10): 867-870
Abstract:
A Convenient method for the synthesis of fused phosphorusheterocycle 1,3,2-oxazaphosphorin-[3,2-a]-8-oxo-l0-thio(or seleno)-[1,3,2]-benzodiazaphosphorines was carried out in one pot by the reaction of Tris(diethylamino)phosphine with multifunctional compounds 2-(N-(β or y-hydroxyl) alkylene) amino-benzamides 1. When PCL3, was used, only chlorinated product was obtained.
A Convenient method for the synthesis of fused phosphorusheterocycle 1,3,2-oxazaphosphorin-[3,2-a]-8-oxo-l0-thio(or seleno)-[1,3,2]-benzodiazaphosphorines was carried out in one pot by the reaction of Tris(diethylamino)phosphine with multifunctional compounds 2-(N-(β or y-hydroxyl) alkylene) amino-benzamides 1. When PCL3, was used, only chlorinated product was obtained.
2000, 11(10): 871-872
Abstract:
A perchoric acid-induced lactonization reaction of epoxy ester is described. Using lithium perchlorate, the ketone is obtained in 81% yield.
A perchoric acid-induced lactonization reaction of epoxy ester is described. Using lithium perchlorate, the ketone is obtained in 81% yield.
2000, 11(10): 873-874
Abstract:
Agarofuranoids with oxygen functions at C-1 and C-2 were synthesized by allylic oxidation. Ketone 2 gave compound 8 and 9 by Grignard reaction. The configuration of C-2 in 8 and 9 were identified by the CD spectroscopy of the benzoate 10.
Agarofuranoids with oxygen functions at C-1 and C-2 were synthesized by allylic oxidation. Ketone 2 gave compound 8 and 9 by Grignard reaction. The configuration of C-2 in 8 and 9 were identified by the CD spectroscopy of the benzoate 10.
2000, 11(10): 875-878
Abstract:
Four 1,4-benzodioxane neolignans were first synthesized from pyrogallol, in which the Claisen rearrangement was used to afford three important C6-C3 units.
Four 1,4-benzodioxane neolignans were first synthesized from pyrogallol, in which the Claisen rearrangement was used to afford three important C6-C3 units.
2000, 11(10): 879-882
Abstract:
This paper reports a continous study of the use of short chain peptides as carriers of a potential antitumor agents:2,6-dimethoxyhydroquinone-3-mercaptoacetic acid (DMQ-MA). In an effort to carry out anti-cancer drug design, we synthesized another two new DMQ-MA-peptide-chlorambucil (CRB) derivatives:DMQ-MA-Lys(CRB)-Arg-OMe, DMQ-MA-Lys(DMQ-MA)-Lys(CRB)-Arg-OMe. These peptide-chlorambucil conjugates were synthesized by coupling protected amino acids in solution and the next conjugation was achieved by reacting with pentafluorophenyl ester of DMQ-MA in DMF. The CRB in side chain was coupled by deblocking the lysyl-carbobenzyloxy protecting group Z and then reacting with the pentafluorophenyl ester of chlorambucil (CRB). Further study on cytotoxicity, DNA binding, and sequence specificity of DNA alkylation of these two new conjugates are investigating.
This paper reports a continous study of the use of short chain peptides as carriers of a potential antitumor agents:2,6-dimethoxyhydroquinone-3-mercaptoacetic acid (DMQ-MA). In an effort to carry out anti-cancer drug design, we synthesized another two new DMQ-MA-peptide-chlorambucil (CRB) derivatives:DMQ-MA-Lys(CRB)-Arg-OMe, DMQ-MA-Lys(DMQ-MA)-Lys(CRB)-Arg-OMe. These peptide-chlorambucil conjugates were synthesized by coupling protected amino acids in solution and the next conjugation was achieved by reacting with pentafluorophenyl ester of DMQ-MA in DMF. The CRB in side chain was coupled by deblocking the lysyl-carbobenzyloxy protecting group Z and then reacting with the pentafluorophenyl ester of chlorambucil (CRB). Further study on cytotoxicity, DNA binding, and sequence specificity of DNA alkylation of these two new conjugates are investigating.
2000, 11(10): 883-886
Abstract:
New electron donors with hydroxyl groups were synthesized and characterized spectroscopically. Their redox potentials were determined with cyclic voltammetry, and the comparison with BEDT-TTF [Bis(ethylenedithio)tetrathiafulvalene] in this aspect was made. These results indicated that the new electron donors had similar electron-donating capabilities as BEDT-TTF.
New electron donors with hydroxyl groups were synthesized and characterized spectroscopically. Their redox potentials were determined with cyclic voltammetry, and the comparison with BEDT-TTF [Bis(ethylenedithio)tetrathiafulvalene] in this aspect was made. These results indicated that the new electron donors had similar electron-donating capabilities as BEDT-TTF.
2000, 11(10): 887-890
Abstract:
A novel caged bicyclic phosphate flame retardant tri(1-oxo-2,6,7-trioxa-I-phosphabicyclo [2.2.2] octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicvclo [2.2.2] octane (PEPAI and phosphorus oxychloride in this paper. Its structure was characterized by elemental analysis, FTIR. 1H NMR, 1P NMR and X-ray diffraction analysis.
A novel caged bicyclic phosphate flame retardant tri(1-oxo-2,6,7-trioxa-I-phosphabicyclo [2.2.2] octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicvclo [2.2.2] octane (PEPAI and phosphorus oxychloride in this paper. Its structure was characterized by elemental analysis, FTIR. 1H NMR, 1P NMR and X-ray diffraction analysis.
2000, 11(10): 891-892
Abstract:
A complete potential energy surface for the CHCIFOH system was calculated at the G3(MP2) level. The calculations reveal that the four-center 1.2-HX (X=F. CI) elimination mechanism rather than the bond scission mechanism dominate decomposition of CHCIFOH. The results are valuable to understand the atmospheric chemistry of HCFC-31.
A complete potential energy surface for the CHCIFOH system was calculated at the G3(MP2) level. The calculations reveal that the four-center 1.2-HX (X=F. CI) elimination mechanism rather than the bond scission mechanism dominate decomposition of CHCIFOH. The results are valuable to understand the atmospheric chemistry of HCFC-31.
2000, 11(10): 893-894
Abstract:
This investigation developed a new method for determining metal complex's property containing the stepwise real absorptivity (ε) and stability constant (Km). The correction equation of the multi-wavelength spectral absorption was established for the simultaneous determination of various complexes to give high accuracy for trace analysis. This method was more acceptable in theory and simpler in operation than the classical methods.
This investigation developed a new method for determining metal complex's property containing the stepwise real absorptivity (ε) and stability constant (Km). The correction equation of the multi-wavelength spectral absorption was established for the simultaneous determination of various complexes to give high accuracy for trace analysis. This method was more acceptable in theory and simpler in operation than the classical methods.
2000, 11(10): 895-896
Abstract:
A new tlavonoid, namely pinnatifine I (1), was isolated from the leaves of Crataegus pinnatifida Bge, var. major N.E.Br.. Its structure was elucidated by spectroscopic analysis and chemical evidence.
A new tlavonoid, namely pinnatifine I (1), was isolated from the leaves of Crataegus pinnatifida Bge, var. major N.E.Br.. Its structure was elucidated by spectroscopic analysis and chemical evidence.
2000, 11(10): 897-990
Abstract:
A pregnane glycoside and a lignan glycoside were isolated from the aerial parts of Rubes amabilis. Their structures were elucidated as 3-O-β-D-glucopyranosyl-3β.15α-dihydroxypregn-5-en-20-one and(-)-secoisolariciresinol-O-α-L-rhamnopyranoside using spectroscopic and chemical methods.
A pregnane glycoside and a lignan glycoside were isolated from the aerial parts of Rubes amabilis. Their structures were elucidated as 3-O-β-D-glucopyranosyl-3β.15α-dihydroxypregn-5-en-20-one and(-)-secoisolariciresinol-O-α-L-rhamnopyranoside using spectroscopic and chemical methods.
2000, 11(10): 901-904
Abstract:
Two new C27, steroidal glycosides, named ophiopojaponin A (1)and B (2), were isolated from the tubers of famous traditional Chinese herb-Ophiopogon japonicus. The spectroscopic and chemical evidences revealed their structures to be Pennogenin 3-O-[2'-O-acetyl-α-L-rhamnopyranosyl (1→2)]-B-D-xylopyranosyl(1→3)-[3-D-glucopyranoside (1) and 26-O-β-D-glucopyranosyl-(22ξ, 25R)-3β, 14α, 22ξ, 26-tetrahydroxyfurost-5-ene 3-O-α-L-rhamnopyranosyl (1→2)-(β-D-glucopyranoside (2), respectively.
Two new C27, steroidal glycosides, named ophiopojaponin A (1)and B (2), were isolated from the tubers of famous traditional Chinese herb-Ophiopogon japonicus. The spectroscopic and chemical evidences revealed their structures to be Pennogenin 3-O-[2'-O-acetyl-α-L-rhamnopyranosyl (1→2)]-B-D-xylopyranosyl(1→3)-[3-D-glucopyranoside (1) and 26-O-β-D-glucopyranosyl-(22ξ, 25R)-3β, 14α, 22ξ, 26-tetrahydroxyfurost-5-ene 3-O-α-L-rhamnopyranosyl (1→2)-(β-D-glucopyranoside (2), respectively.
2000, 11(10): 905-908
Abstract:
Two new sesquiterpene lactones, notoserolides A and B, along with 12 known compounds were isolated from the aerial parts of Notoseris porphyrolepis. By means of spectral methods including MS, NMR (1H NMR. 13C NMR, DFPT, HMQC. HMBC) and X-ray diffraction. as well as chemical reactions. the structures of notoserolides A and Q were established as austricin 8-O-β-D-glucopyranoside and 8-O-senecioylaustricin, respectively.
Two new sesquiterpene lactones, notoserolides A and B, along with 12 known compounds were isolated from the aerial parts of Notoseris porphyrolepis. By means of spectral methods including MS, NMR (1H NMR. 13C NMR, DFPT, HMQC. HMBC) and X-ray diffraction. as well as chemical reactions. the structures of notoserolides A and Q were established as austricin 8-O-β-D-glucopyranoside and 8-O-senecioylaustricin, respectively.
2000, 11(10): 909-912
Abstract:
A novel dammarane-type triterpene oligoglycoside, named ginsenoside-Rg6, 3, was isolated from the stem-leaves of Panax ginseng C. A. Mey., together with two known ones. 20(S)-ginsenoside-Rg2 1 and 20(R)-ginsenoside-Rg2 2. On the basis of chemical and physicochemical evidence. the structure of ginsenoside-Rg6 have been elucidated as 6-O-α-L-rhamnosyl-(1→2)-β-D-glucopyranosyl-dammarane-(E)-20(22), 24-diene-3β. 6α, 12β-triol.
A novel dammarane-type triterpene oligoglycoside, named ginsenoside-Rg6, 3, was isolated from the stem-leaves of Panax ginseng C. A. Mey., together with two known ones. 20(S)-ginsenoside-Rg2 1 and 20(R)-ginsenoside-Rg2 2. On the basis of chemical and physicochemical evidence. the structure of ginsenoside-Rg6 have been elucidated as 6-O-α-L-rhamnosyl-(1→2)-β-D-glucopyranosyl-dammarane-(E)-20(22), 24-diene-3β. 6α, 12β-triol.
2000, 11(10): 913-914
Abstract:
A new oleanane-type saponin. named subcapitatoside A. has been isolated from the rtrdts of Aralia subcapitata. On the basis of chemical and spectral evidence. the structure of subcanitatoside A has been established as:3-O-β-D-galactopyranosyl-(1→2)-(3-D-galacto-pyranosyl oleanolic acid.
A new oleanane-type saponin. named subcapitatoside A. has been isolated from the rtrdts of Aralia subcapitata. On the basis of chemical and spectral evidence. the structure of subcanitatoside A has been established as:3-O-β-D-galactopyranosyl-(1→2)-(3-D-galacto-pyranosyl oleanolic acid.
2000, 11(10): 915-918
Abstract:
In this paper, the formation mechanism of the passive SFI film at the natural graphite anodes was investigated with the electrochemical impedance spectroscopy (EIS). A characteristic semicircle was observed in the lower frequency range of the EIS spectrum for the irreversible charge process (lithium intercalation) at ca. 0.75V, 0.40V and 0.20V.
In this paper, the formation mechanism of the passive SFI film at the natural graphite anodes was investigated with the electrochemical impedance spectroscopy (EIS). A characteristic semicircle was observed in the lower frequency range of the EIS spectrum for the irreversible charge process (lithium intercalation) at ca. 0.75V, 0.40V and 0.20V.
2000, 11(10): 919-920
Abstract:
Abstract The electrochemical properties of MEH-PPV were studied in ionic liquid([bmim]+[PF6]-) by cyclic voltammetry, chronoamperometry and AC impedance measurements. Both p-and n-doping of MEH-PPV were observed in the cyclic voltammograms. The chronoamperometric and AC impedance results indicate that the p-doping of MEH-PPV was controlled by the linear diffusion of counterions.
Abstract The electrochemical properties of MEH-PPV were studied in ionic liquid([bmim]+[PF6]-) by cyclic voltammetry, chronoamperometry and AC impedance measurements. Both p-and n-doping of MEH-PPV were observed in the cyclic voltammograms. The chronoamperometric and AC impedance results indicate that the p-doping of MEH-PPV was controlled by the linear diffusion of counterions.
2000, 11(10): 921-924
Abstract:
Octadecylamine was derivatized with dansyl chloride (5-dimethylaminonaphthalene-l-sulfonyl chloride) in order to simplify and understand the LB films of fluorescent probe labeling proteins. Its monolayer and multilayers in the absence and presence of stearic acid were deposited by LB technique. Fluorescence spectra and lifetimes of the fluorescent products were studied to elucidate the microenvironment of molecules in the LB films.
Octadecylamine was derivatized with dansyl chloride (5-dimethylaminonaphthalene-l-sulfonyl chloride) in order to simplify and understand the LB films of fluorescent probe labeling proteins. Its monolayer and multilayers in the absence and presence of stearic acid were deposited by LB technique. Fluorescence spectra and lifetimes of the fluorescent products were studied to elucidate the microenvironment of molecules in the LB films.
2000, 11(10): 925-928
Abstract:
The recovery of amorphous PET fiber in global chain orientation but nearly random segmental orientation (GOLR) state was studied by the hot shrinkage measurement above the glass transition temperature. The relaxation curves in the form of di-exponential decay were acquired and the change of two special times with the variation of treating temperature and residual recovery ratio η was discussed.
The recovery of amorphous PET fiber in global chain orientation but nearly random segmental orientation (GOLR) state was studied by the hot shrinkage measurement above the glass transition temperature. The relaxation curves in the form of di-exponential decay were acquired and the change of two special times with the variation of treating temperature and residual recovery ratio η was discussed.
2000, 11(10): 929-930
Abstract:
The UV-Vis spectra of THPPH2 in CTAB micelles at pH7.2 and pH11.0 were analyzed to study the effect of micellar environments on the aggregation behaviors of this porphyrin.
The UV-Vis spectra of THPPH2 in CTAB micelles at pH7.2 and pH11.0 were analyzed to study the effect of micellar environments on the aggregation behaviors of this porphyrin.
2000, 11(10): 931-932
Abstract:
The phase transition of two kinds of solvent-induced crystalline syndiotactic polystyrene (sPS), γ -sPS and δe-sPS, has been studied via WAXD and DSC. γ-sPS transform to α-sPS at 195-225℃ before melt during heating, whereas δe-sPS transform to first γ-sPS and then α-sPS at 100-200℃ and 200-215℃, respectively. The transition of δe-γ and γ-α occurs far below melting point of sPS indicates they are all solid-solid transition.
The phase transition of two kinds of solvent-induced crystalline syndiotactic polystyrene (sPS), γ -sPS and δe-sPS, has been studied via WAXD and DSC. γ-sPS transform to α-sPS at 195-225℃ before melt during heating, whereas δe-sPS transform to first γ-sPS and then α-sPS at 100-200℃ and 200-215℃, respectively. The transition of δe-γ and γ-α occurs far below melting point of sPS indicates they are all solid-solid transition.
2000, 11(10): 933-934
Abstract:
Effect of CO2 dissolved in tetrahydrofuran (THF) on the polymerization of styrene in THF was studied at 333.2 K and different pressures. It was found that the molecular weight (MW) and MW distribution of the polystyrene (PS) could be controlled by pressure.
Effect of CO2 dissolved in tetrahydrofuran (THF) on the polymerization of styrene in THF was studied at 333.2 K and different pressures. It was found that the molecular weight (MW) and MW distribution of the polystyrene (PS) could be controlled by pressure.
2000, 11(10): 935-936
Abstract:
A novel polymeric complex[La(bipyN2O2)(TFA)3]n (TFA=trifluoroacetylacetone) was prepared. The X-ray structure analysis revealed that the complex has an infinite one-dimensional supramolecule structure with the 4,4'-bipyridyl-N,N'-dioxide as a bridge. La(Ⅲ) is coordinated to eight oxygen atoms, six from three trifluoroacetylacetonate anions, two from two 4,4'-bipyridyl-N,N'-dioxide molecules.
A novel polymeric complex[La(bipyN2O2)(TFA)3]n (TFA=trifluoroacetylacetone) was prepared. The X-ray structure analysis revealed that the complex has an infinite one-dimensional supramolecule structure with the 4,4'-bipyridyl-N,N'-dioxide as a bridge. La(Ⅲ) is coordinated to eight oxygen atoms, six from three trifluoroacetylacetonate anions, two from two 4,4'-bipyridyl-N,N'-dioxide molecules.
2000, 11(10): 937-940
Abstract:
A combined EDTA-citrate complexing method was developed for the easy preparation of mixed oxygen-ionic and electronic conducting dense ceramic membrane for oxygen separation The new method takes the advantage-of lower calcination temperature for phase formation, lower membrane sintering temperature and higher relative density over the standard ceramic method.
A combined EDTA-citrate complexing method was developed for the easy preparation of mixed oxygen-ionic and electronic conducting dense ceramic membrane for oxygen separation The new method takes the advantage-of lower calcination temperature for phase formation, lower membrane sintering temperature and higher relative density over the standard ceramic method.
