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2000 Volume 11 Issue 6
2000, 11(6): 471-472
Abstract:
A reversed-phase high-performance liquid chromatographic method for the separation and quantitation of 1,4-phenylenediamine, 4-aminophenol, 3-aminophenol, 1,3-benzendiol and 2,6-phenylenediamine in hair dyes was developed. The separation was carried out on a μ-Bondapak C18 column with methanol-water containing 0.1% triethylamine and 0.02 mol/L NH4Ac (pH=5.20) (10:90, vol./vol.) as the mobile phase. Two real samples were analyzed.
A reversed-phase high-performance liquid chromatographic method for the separation and quantitation of 1,4-phenylenediamine, 4-aminophenol, 3-aminophenol, 1,3-benzendiol and 2,6-phenylenediamine in hair dyes was developed. The separation was carried out on a μ-Bondapak C18 column with methanol-water containing 0.1% triethylamine and 0.02 mol/L NH4Ac (pH=5.20) (10:90, vol./vol.) as the mobile phase. Two real samples were analyzed.
2000, 11(6): 473-474
Abstract:
Reduction of diaryldiselenides by the system of Cp2TiCl2/BuiMgBr/THF gave the nucleophilic arylselenium complex. They reacted with diaryl iodonium salts to afford unsymmetrical diaryl selenides in high yields.
Reduction of diaryldiselenides by the system of Cp2TiCl2/BuiMgBr/THF gave the nucleophilic arylselenium complex. They reacted with diaryl iodonium salts to afford unsymmetrical diaryl selenides in high yields.
2000, 11(6): 475-478
Abstract:
An unexpected tricyclic compound 2,3,3a,4,5,9b-hexahydrophenylfuro[3,2-c] quinoline 4 and its aromatized product 6 were obtained when the cycloaddtion of imine 1 and substituted norbornene 2 was carried out in THF with a catalytic amount of boron trifluoride. The structures of the products were determined by spectral data, and the mechanism of reaction was substantiated by the imitation reaction.
An unexpected tricyclic compound 2,3,3a,4,5,9b-hexahydrophenylfuro[3,2-c] quinoline 4 and its aromatized product 6 were obtained when the cycloaddtion of imine 1 and substituted norbornene 2 was carried out in THF with a catalytic amount of boron trifluoride. The structures of the products were determined by spectral data, and the mechanism of reaction was substantiated by the imitation reaction.
2000, 11(6): 479-482
Abstract:
The photoinduced one-electron reduction of 1,4-dihydroxyanthraquinone(1,4-DHAQ) was studied by fluorescence, absorption and ESR spectroscopics.
The photoinduced one-electron reduction of 1,4-dihydroxyanthraquinone(1,4-DHAQ) was studied by fluorescence, absorption and ESR spectroscopics.
2000, 11(6): 483-484
Abstract:
Promoted by SmI3, β-diketones, β-ketoesters and α-cyano esters were added to α,β-unsaturated esters to form δ-carbonyl esters in mild conditions in moderate to good yields.
Promoted by SmI3, β-diketones, β-ketoesters and α-cyano esters were added to α,β-unsaturated esters to form δ-carbonyl esters in mild conditions in moderate to good yields.
2000, 11(6): 485-488
Abstract:
Aldolase models derived from calix[4]arene were designed and synthesized. The aldol condensation of p-nitrobenzaldehyde with acetone was catalyzed by the synthetic enzymes proceeded under mild conditions to offer chiefly aldol-type product in good yield.
Aldolase models derived from calix[4]arene were designed and synthesized. The aldol condensation of p-nitrobenzaldehyde with acetone was catalyzed by the synthetic enzymes proceeded under mild conditions to offer chiefly aldol-type product in good yield.
2000, 11(6): 489-492
Abstract:
Some of the chemical reactions of 11-hydroxycephalotaxine 1, which were encountered during the derivation of 1 and the related compounds were reported.
Some of the chemical reactions of 11-hydroxycephalotaxine 1, which were encountered during the derivation of 1 and the related compounds were reported.
2000, 11(6): 493-494
Abstract:
6-Deoxy-6-iodo-β-cyclodextrin (1) reacted with 5-(p-aminophenyl)-10,15,20-triphenyl porphyrin(2), 5-(p-aminophenyl)-10,15,20-triphenyl nickel(Ⅱ) porphyrin[NiⅡTPPNH2P] (3), 5-(p-aminophenyl)-10,15,20-triphenyl manganese(Ⅲ) porphyrin[MnⅢTPPNH2P] (4) and 5-(p-aminophenyl)-10,15,20-triphenyl carbonyl ruthenium porphyrin[RuⅡ(CO)TPPNH2P] (5) to generate the compounds 6-9, respectively. Those new compound 5-9 have been identified by 1H NMR, IR, MS and UV-visible spectra and elemental analysis.
6-Deoxy-6-iodo-β-cyclodextrin (1) reacted with 5-(p-aminophenyl)-10,15,20-triphenyl porphyrin(2), 5-(p-aminophenyl)-10,15,20-triphenyl nickel(Ⅱ) porphyrin[NiⅡTPPNH2P] (3), 5-(p-aminophenyl)-10,15,20-triphenyl manganese(Ⅲ) porphyrin[MnⅢTPPNH2P] (4) and 5-(p-aminophenyl)-10,15,20-triphenyl carbonyl ruthenium porphyrin[RuⅡ(CO)TPPNH2P] (5) to generate the compounds 6-9, respectively. Those new compound 5-9 have been identified by 1H NMR, IR, MS and UV-visible spectra and elemental analysis.
2000, 11(6): 495-498
Abstract:
The intermolecular reductive coupling of nitriles with azobenzene induced by SmI2 was studied. Amidine derivatives were prepared in good yields under neutral and mild conditions.
The intermolecular reductive coupling of nitriles with azobenzene induced by SmI2 was studied. Amidine derivatives were prepared in good yields under neutral and mild conditions.
2000, 11(6): 499-502
Abstract:
Condensation of 3,7-dichloromethyl-5-isopropyl-2-methoxytropone 4 with bis (mer-captoethyl) ether 5a and mono, di, and tri-ethylene glycol bis(mercaptoethyl) ethers 5b-5d gave troponoid-annexed dithiocrown ethers 6a-6d. Compounds 6a-6d have selective and reversible mercury salt capturing ability.
Condensation of 3,7-dichloromethyl-5-isopropyl-2-methoxytropone 4 with bis (mer-captoethyl) ether 5a and mono, di, and tri-ethylene glycol bis(mercaptoethyl) ethers 5b-5d gave troponoid-annexed dithiocrown ethers 6a-6d. Compounds 6a-6d have selective and reversible mercury salt capturing ability.
2000, 11(6): 503-504
Abstract:
3-Acetyltropolone 1 reacted with 3,4,5-trimethoxybenzaldehyde et al. to afford 2~5. 2-Acetyl-7-methylaminotropone 7 reacted with 3,4,5-trimethoxybenzaldehyde et al. to gave 8~10. Compound 1 reacted with 3,4,5-trimethoxybenzaldehyde in the presence of ethyl orthoformate and perchloric acid to afford 6. Compounds 3,5 reacted with hydroxylamine to give 11, 12. The reactions of 3,5 with phenylhydrazine gave 13, 14.
3-Acetyltropolone 1 reacted with 3,4,5-trimethoxybenzaldehyde et al. to afford 2~5. 2-Acetyl-7-methylaminotropone 7 reacted with 3,4,5-trimethoxybenzaldehyde et al. to gave 8~10. Compound 1 reacted with 3,4,5-trimethoxybenzaldehyde in the presence of ethyl orthoformate and perchloric acid to afford 6. Compounds 3,5 reacted with hydroxylamine to give 11, 12. The reactions of 3,5 with phenylhydrazine gave 13, 14.
2000, 11(6): 505-508
Abstract:
4-β-Cyano-4-deoxy-4'-demethylepipodophyllotoxin 4 was synthesized from 4'-de-methylepipodophyllotoxin and Me3SiCN in the presence of BF3·Et2O. 4-β-Carboxyl-4-deoxy-4'-demethylepipodophyllotoxin 5 was obtained by hydrolyzing 4 in HOAc. Both of them show very high anticancer activities against L1210 and KB cell lines in vitro.
4-β-Cyano-4-deoxy-4'-demethylepipodophyllotoxin 4 was synthesized from 4'-de-methylepipodophyllotoxin and Me3SiCN in the presence of BF3·Et2O. 4-β-Carboxyl-4-deoxy-4'-demethylepipodophyllotoxin 5 was obtained by hydrolyzing 4 in HOAc. Both of them show very high anticancer activities against L1210 and KB cell lines in vitro.
2000, 11(6): 509-510
Abstract:
An efficient and stereoselective synthetic procedure for (3S,5S,6R)-3,7-dimethyl-5,6,7-trihydroxy-octanal derivative, the intermediate for synthetic of the HIV-active didemnaketals analogue, was developed via a series of reactions from the natural (+)-Pulegone. In this approach, an efficient diastereoselective reaction of the epoxides 8 and 9 with PCC has been accomplished.
An efficient and stereoselective synthetic procedure for (3S,5S,6R)-3,7-dimethyl-5,6,7-trihydroxy-octanal derivative, the intermediate for synthetic of the HIV-active didemnaketals analogue, was developed via a series of reactions from the natural (+)-Pulegone. In this approach, an efficient diastereoselective reaction of the epoxides 8 and 9 with PCC has been accomplished.
2000, 11(6): 511-512
Abstract:
A new polysiloxane containing octaphenylcyclodisilazane was synthesized from the anionic polymerization of octamethylcyclotetrasiloxane (D4) and "seed solution" as initiator, which was prepared by hexamethylcyclotrisiloxane (D3) and the lithium salt of N,N'-bis (hydroxydi-phenyl)tetraphenylcyclodisilazane.
A new polysiloxane containing octaphenylcyclodisilazane was synthesized from the anionic polymerization of octamethylcyclotetrasiloxane (D4) and "seed solution" as initiator, which was prepared by hexamethylcyclotrisiloxane (D3) and the lithium salt of N,N'-bis (hydroxydi-phenyl)tetraphenylcyclodisilazane.
2000, 11(6): 513-514
Abstract:
An efficient synthetic route have been developed to 16-acetoxy-6,7-didehydroferruginyl methyl ether.
An efficient synthetic route have been developed to 16-acetoxy-6,7-didehydroferruginyl methyl ether.
2000, 11(6): 515-516
Abstract:
The oxidative coupling reaction of isorhapontigenin using sliver oxide as oxidant afforded a major product, named shegansu B (2), which was isolated from the roots of Belamcanda chinensis (L.) DC. Both the natural and synthetic Shegansu B have the same potent antagonism activities of leukotriene B4, D4 receptor.
The oxidative coupling reaction of isorhapontigenin using sliver oxide as oxidant afforded a major product, named shegansu B (2), which was isolated from the roots of Belamcanda chinensis (L.) DC. Both the natural and synthetic Shegansu B have the same potent antagonism activities of leukotriene B4, D4 receptor.
2000, 11(6): 517-520
Abstract:
The derivatives of b-alkoxycarbonylethyltin trichlorides with diethyldithiocarbamate, ROCOCH2CH2Sn(S2CNEt2)Cl2, were synthesized and characterized by the means of elemental analysis, IR, 1H NMR and X-ray single crystal diffraction. The structural features of the compounds were described, and the possible mechanism of transesterification for compound 2a was suggested.
The derivatives of b-alkoxycarbonylethyltin trichlorides with diethyldithiocarbamate, ROCOCH2CH2Sn(S2CNEt2)Cl2, were synthesized and characterized by the means of elemental analysis, IR, 1H NMR and X-ray single crystal diffraction. The structural features of the compounds were described, and the possible mechanism of transesterification for compound 2a was suggested.
2000, 11(6): 521-524
Abstract:
The catalytic hydroesterification of methyl formate (MF) with acetylene to methyl acrylate (MA) over nickel-based catalysts prepared by impregnation has been comprehensively studied in a fixed bed reactor at 160~240℃ and under 4~6MPa, GHSV:630h-1, CO:N2:C2H2=65:28:7. In present work, we have found a catalyst of 11wt%NiO/Al2O3 (80~100 mesh) prepared by wet impregnation with NiCl2 aqueous solution, then calcined in air at 500℃ for 5 h. The selectivity to methyl acrylate and the conversion of methyl formate over 11wt%NiO/Al2O3 catalyst are higher than other catalysts studied in this paper. The optimum reaction temperature for the hydroesterification of methyl formate with acetylene to methyl acrylate is around 220℃.
The catalytic hydroesterification of methyl formate (MF) with acetylene to methyl acrylate (MA) over nickel-based catalysts prepared by impregnation has been comprehensively studied in a fixed bed reactor at 160~240℃ and under 4~6MPa, GHSV:630h-1, CO:N2:C2H2=65:28:7. In present work, we have found a catalyst of 11wt%NiO/Al2O3 (80~100 mesh) prepared by wet impregnation with NiCl2 aqueous solution, then calcined in air at 500℃ for 5 h. The selectivity to methyl acrylate and the conversion of methyl formate over 11wt%NiO/Al2O3 catalyst are higher than other catalysts studied in this paper. The optimum reaction temperature for the hydroesterification of methyl formate with acetylene to methyl acrylate is around 220℃.
2000, 11(6): 525-526
Abstract:
PU/P(UBMI-BMI) IPNs with excellent thermal stability and mechanical properties were synthesized and characterized. The interpenetrating occurs in the hard segment domains of PU, which leads to enhancement of hydrogen bonding of N-H, and narrow-distributed small size of the dispersed phase.
PU/P(UBMI-BMI) IPNs with excellent thermal stability and mechanical properties were synthesized and characterized. The interpenetrating occurs in the hard segment domains of PU, which leads to enhancement of hydrogen bonding of N-H, and narrow-distributed small size of the dispersed phase.
2000, 11(6): 527-530
Abstract:
The electron transfer reaction between triplet anthraquinone-2-sulfonate with poly-guanylic acid (5) (poly[G]) in acetonitrile-H2O has been investigated by 248 nm laser flash photolysis. The transient absorption spectra of radical cation of poly[G] and radical anion of anthraqunione-2-sulfonate(AQS) arising from electron transfer reaction has been observed simultaneously for the first time. The formation processes of radical cation of poly[G] and radical anion of anthraquinone-2-sulfonate as well as the decay processes of triplet anthraquinone-2-sulfonate have also been observed, the apparent rate constants for the formation and decay of transient species have been determined. The free energy changes in the process of the electron transfer was also calculated.
The electron transfer reaction between triplet anthraquinone-2-sulfonate with poly-guanylic acid (5) (poly[G]) in acetonitrile-H2O has been investigated by 248 nm laser flash photolysis. The transient absorption spectra of radical cation of poly[G] and radical anion of anthraqunione-2-sulfonate(AQS) arising from electron transfer reaction has been observed simultaneously for the first time. The formation processes of radical cation of poly[G] and radical anion of anthraquinone-2-sulfonate as well as the decay processes of triplet anthraquinone-2-sulfonate have also been observed, the apparent rate constants for the formation and decay of transient species have been determined. The free energy changes in the process of the electron transfer was also calculated.
2000, 11(6): 531-534
Abstract:
Two new sterol have been isolated from the South China Sea marine organism. Compound 1 was isolated from the sponge Polymastia sobustia and compound 2 was obtained from the soft coral Sinularia inexplicata. Their structures were established as 3β-hydroxy-stigmast-5en-7-one and 24-methylene cholestan-3β, 6β, 9α, 19-tetrol by variety of spectral analysis such as IR, EIMS, 1DNMR, 1H-1H COSY, HMQC, HMBC, NOESY.
Two new sterol have been isolated from the South China Sea marine organism. Compound 1 was isolated from the sponge Polymastia sobustia and compound 2 was obtained from the soft coral Sinularia inexplicata. Their structures were established as 3β-hydroxy-stigmast-5en-7-one and 24-methylene cholestan-3β, 6β, 9α, 19-tetrol by variety of spectral analysis such as IR, EIMS, 1DNMR, 1H-1H COSY, HMQC, HMBC, NOESY.
2000, 11(6): 535-538
Abstract:
Two new sterols, 3β,7α,16β-trihydroxy-stigmast-5,22-diene 1, 3β,7α,16β-trihydroxy-stigmast-5-ene 2, were isolated together with two known ergosterols, ergosta-5,24(28)-diene-3β,7α-diol, ergosta-5,24(28)-diene-3β,7β,16β-triol from the bark of Amoora yunnanensis (H. L. Li) C. Y. Wu. Their structures were deduced on the basis of spectral data.
Two new sterols, 3β,7α,16β-trihydroxy-stigmast-5,22-diene 1, 3β,7α,16β-trihydroxy-stigmast-5-ene 2, were isolated together with two known ergosterols, ergosta-5,24(28)-diene-3β,7α-diol, ergosta-5,24(28)-diene-3β,7β,16β-triol from the bark of Amoora yunnanensis (H. L. Li) C. Y. Wu. Their structures were deduced on the basis of spectral data.
2000, 11(6): 539-542
Abstract:
Two new O-terpenoidal coumarins named excavacoumarin A (2), B (3), and a known one 1 were isolated from the leaves of Clausena excavata Burm. f. (Rutaceae) collected in Xishuangbanna, Yunnan. Structure elucidation and unambiguous NMR assignments for the title compounds were carried out on the basis of 1D and 2D NMR experiments.
Two new O-terpenoidal coumarins named excavacoumarin A (2), B (3), and a known one 1 were isolated from the leaves of Clausena excavata Burm. f. (Rutaceae) collected in Xishuangbanna, Yunnan. Structure elucidation and unambiguous NMR assignments for the title compounds were carried out on the basis of 1D and 2D NMR experiments.
2000, 11(6): 543-544
Abstract:
Two mild-cytotoxic bistetrahydrofuran (THF) ring annonaceous acetogenins named calamistrins F (1) and G (2) were isolated from the ethanolic extract of the roots of U. calamistrata Hance. Their structures including the relative and absolute configurations were determined by chemical derivation and spectral analysis. Calamistrins F and G were a pair of epimers at C-26 which both had THF ring from C-18 to C-25 and three OH groups at C-5, C-17 and C-26.
Two mild-cytotoxic bistetrahydrofuran (THF) ring annonaceous acetogenins named calamistrins F (1) and G (2) were isolated from the ethanolic extract of the roots of U. calamistrata Hance. Their structures including the relative and absolute configurations were determined by chemical derivation and spectral analysis. Calamistrins F and G were a pair of epimers at C-26 which both had THF ring from C-18 to C-25 and three OH groups at C-5, C-17 and C-26.
2000, 11(6): 545-548
Abstract:
Photodissociation of cyclopentanone (C5H8O) and cyclohexanone (C6H10O) was studied with 800nm, 50fs laser pulse at intensities of 5.0-13.0×1013 W/cm2. A time of flight mass spectrometer was employed to detect the ion signals. Parent ions dominated at lower laser intensities. Fragmentation of the parent ions increases with increasing laser intensity and molecular size. The fragmentation mechanism was discussed.
Photodissociation of cyclopentanone (C5H8O) and cyclohexanone (C6H10O) was studied with 800nm, 50fs laser pulse at intensities of 5.0-13.0×1013 W/cm2. A time of flight mass spectrometer was employed to detect the ion signals. Parent ions dominated at lower laser intensities. Fragmentation of the parent ions increases with increasing laser intensity and molecular size. The fragmentation mechanism was discussed.
2000, 11(6): 549-550
Abstract:
The retention behaviors of benzene and its alkyl homologues in microemulsion electrokinetic chromatography were investigated in both anionic and cationic surfactant MEEKC systems. The effects of the composition of microemulsion on retention time and selectivity were studied. A good linear relationship was obtained between log k and the carbon number of alkyl chain.
The retention behaviors of benzene and its alkyl homologues in microemulsion electrokinetic chromatography were investigated in both anionic and cationic surfactant MEEKC systems. The effects of the composition of microemulsion on retention time and selectivity were studied. A good linear relationship was obtained between log k and the carbon number of alkyl chain.
2000, 11(6): 551-554
Abstract:
A new fluorescent sensor consisted of fluorenyl and dioxotetraaza unit, namely, 2,10-dimethyl-6-(9-fluorenyl)-1,4,8,11-tetraazaundencane-5,7-dione (L), was synthesized. It is a fluorescent sensor for transition metal ions in aqueous solution.
A new fluorescent sensor consisted of fluorenyl and dioxotetraaza unit, namely, 2,10-dimethyl-6-(9-fluorenyl)-1,4,8,11-tetraazaundencane-5,7-dione (L), was synthesized. It is a fluorescent sensor for transition metal ions in aqueous solution.
Structural Multiplicity of Monomers of an Amphiphilic Porphyrin at the Outer Surface of CTAB Micelle
2000, 11(6): 555-558
Abstract:
A synthesized amphiphilic porphyrin, 5,10,15-tri(p-hydroxyphenyl)-20-(p-hexadecyl-oxyphenyl) porphyrin, can take a transfer process for the porphyrin moiety from the inner core to the outer surface layer of cetyltrimethylammonium bromide (CTAB) micelle. The increasing of FWHH of the Soret band was attributed to the multiplicity of porphyrin monomers related with deprotonation degree, arrangement, orientation, and position of porphyrin moiety at the surface area rather than the aggregates associated with irregular orientation of neighboring porphyrins.
A synthesized amphiphilic porphyrin, 5,10,15-tri(p-hydroxyphenyl)-20-(p-hexadecyl-oxyphenyl) porphyrin, can take a transfer process for the porphyrin moiety from the inner core to the outer surface layer of cetyltrimethylammonium bromide (CTAB) micelle. The increasing of FWHH of the Soret band was attributed to the multiplicity of porphyrin monomers related with deprotonation degree, arrangement, orientation, and position of porphyrin moiety at the surface area rather than the aggregates associated with irregular orientation of neighboring porphyrins.
2000, 11(6): 559-560
Abstract:
A novel catalyst precursor, La2NiO4, was investigated to synthesize carbon nanotubes, obtained from catalytic disproportionation of CO. The morphology of carbon nanotubes has been examined by TEM (transmission electron micrograph) and SEM (scaning electron micrograph). It was observed that the Ni nano-particle size formed at different reducing temperatures was a key factor to the yield and diameter of carbon nanotubes.
A novel catalyst precursor, La2NiO4, was investigated to synthesize carbon nanotubes, obtained from catalytic disproportionation of CO. The morphology of carbon nanotubes has been examined by TEM (transmission electron micrograph) and SEM (scaning electron micrograph). It was observed that the Ni nano-particle size formed at different reducing temperatures was a key factor to the yield and diameter of carbon nanotubes.
2000, 11(6): 561-564
Abstract:
CO2-TPD was demonstrated an effective way to investigate the phase formation during pyrolysis for the preparation of composite oxides using metal-organic molecules as precursors. Based on the CO2-TPD results, it was found that calcination condition had deep effect on the carbonate formation and the minimum firing temperature to acquire pure phase composite oxide. An optimized calcination schedule was then developed.
CO2-TPD was demonstrated an effective way to investigate the phase formation during pyrolysis for the preparation of composite oxides using metal-organic molecules as precursors. Based on the CO2-TPD results, it was found that calcination condition had deep effect on the carbonate formation and the minimum firing temperature to acquire pure phase composite oxide. An optimized calcination schedule was then developed.
