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1991 Volume 2 Issue 10
1991, 2(10): 751-752
Abstract:
Carbonyl bis (4'-benzo-15-erown-5) has been synthesized by heating the mixture of benzo-15-crown-5 and 4'-earboxybenzo-15-crawn-5 in polyphosphoric aeid (PPA), and bis (4'-benzo-15-crown-5) carbinol is obtained by reducing carbonyl bis (4'-benzo-15-crown-5) with sodium borahydride. A use ful method is provided to synthesize various types of symmetrical and unsymmetrical bis (crown ether)s.
Carbonyl bis (4'-benzo-15-erown-5) has been synthesized by heating the mixture of benzo-15-crown-5 and 4'-earboxybenzo-15-crawn-5 in polyphosphoric aeid (PPA), and bis (4'-benzo-15-crown-5) carbinol is obtained by reducing carbonyl bis (4'-benzo-15-crown-5) with sodium borahydride. A use ful method is provided to synthesize various types of symmetrical and unsymmetrical bis (crown ether)s.
1991, 2(10): 753-754
Abstract:
The Michael addition of α-chloroesters to α,β-unsaturated systems was catalyzed by traalkylammonium salt in a two-phase solid-liquid system, and some polysubstitnted evclopropanes were facilely synthesized.
The Michael addition of α-chloroesters to α,β-unsaturated systems was catalyzed by traalkylammonium salt in a two-phase solid-liquid system, and some polysubstitnted evclopropanes were facilely synthesized.
1991, 2(10): 755-756
Abstract:
The reaction between 2,5-Dimethylpyrrole (1) and RFI (2) (RF:a, Cl (CF2) 4; b, Cl (CF2) 6; c, Cl (CF2) 8; d, n-C6F13; e, n-C8F17) in the presence of Na2S2O4-NaHCO3 in acetonitrile resulted in the formation of 2-perfluoroalkyl-2,5-dimethyl-2H-pyrrole (3) as a major product in good yield.
The reaction between 2,5-Dimethylpyrrole (1) and RFI (2) (RF:a, Cl (CF2) 4; b, Cl (CF2) 6; c, Cl (CF2) 8; d, n-C6F13; e, n-C8F17) in the presence of Na2S2O4-NaHCO3 in acetonitrile resulted in the formation of 2-perfluoroalkyl-2,5-dimethyl-2H-pyrrole (3) as a major product in good yield.
1991, 2(10): 757-760
Abstract:
Glucosyl phosphotriester of adenosine and glucosyl thiophosphotriester of adenosine were synthesized by phosphite-triester methodology.
Glucosyl phosphotriester of adenosine and glucosyl thiophosphotriester of adenosine were synthesized by phosphite-triester methodology.
1991, 2(10): 761-752
Abstract:
1,7β-Dimethyl-7α-hydroxy-8aα-carboxymethyl-9β-carbomethoxy-4bα, 5, 6, 7, 8, 8α-hexahydrofluorene lactone (2) is converted to 8, 12-epoxyallogibberic acid methyl ester (4) by the action of diisobutyl aluminum hydride (DIBAL-H) with a novel rearrangement reaction.
1,7β-Dimethyl-7α-hydroxy-8aα-carboxymethyl-9β-carbomethoxy-4bα, 5, 6, 7, 8, 8α-hexahydrofluorene lactone (2) is converted to 8, 12-epoxyallogibberic acid methyl ester (4) by the action of diisobutyl aluminum hydride (DIBAL-H) with a novel rearrangement reaction.
1991, 2(10): 763-764
Abstract:
The title compounds are prepared in good yields by iodination of the corresponding flavones, thioflavones and thiochromones respectively using I2-CAN (ceric ammonium nitrate) system. The compounds thus prepared are potentially useful precursors for the synthesis of C-3 linked binuclear compounds.
The title compounds are prepared in good yields by iodination of the corresponding flavones, thioflavones and thiochromones respectively using I2-CAN (ceric ammonium nitrate) system. The compounds thus prepared are potentially useful precursors for the synthesis of C-3 linked binuclear compounds.
1991, 2(10): 765-768
Abstract:
Second order nonlinear optical active 2,3-dichloro-5,6-dicyanopyrazine (DCDCP) and its monoamine-substituted derivatives had been synthesized. Their facile synthesis, high melt point, high incidence af substantial SHG activity and increased transparency inthe blue and near infrared make this class compounds appealling for further investigation.
Second order nonlinear optical active 2,3-dichloro-5,6-dicyanopyrazine (DCDCP) and its monoamine-substituted derivatives had been synthesized. Their facile synthesis, high melt point, high incidence af substantial SHG activity and increased transparency inthe blue and near infrared make this class compounds appealling for further investigation.
1991, 2(10): 769-772
Abstract:
A novel CF3-containing building block, (Z)-ethyl 3-bromo-4,4,4-trifluoro-2-butenoate, was easily prepared from CF3CBr3, the former reacted with alkynes Or organozinc reagents in the presence of Pd complexes to afford useful CF3-containing intermediates in good yield.
A novel CF3-containing building block, (Z)-ethyl 3-bromo-4,4,4-trifluoro-2-butenoate, was easily prepared from CF3CBr3, the former reacted with alkynes Or organozinc reagents in the presence of Pd complexes to afford useful CF3-containing intermediates in good yield.
1991, 2(10): 773-774
Abstract:
4-Aryl-5-ethoxycarbonyl-1-H-1,2,3-triazoles have been prepared by treatment of ethyl polystyrylsulfonylacetate with substituted benzaldehydes and then sodium azide.
4-Aryl-5-ethoxycarbonyl-1-H-1,2,3-triazoles have been prepared by treatment of ethyl polystyrylsulfonylacetate with substituted benzaldehydes and then sodium azide.
1991, 2(10): 775-776
Abstract:
The spectral data and chemical properties of two new amides isolated from Clausena lansium led to the assignment of acyclic structures of C-6 and C-7. The absolute configurations of the two chiral carbons in C-6 were determined by degradation to be 3S4R.
The spectral data and chemical properties of two new amides isolated from Clausena lansium led to the assignment of acyclic structures of C-6 and C-7. The absolute configurations of the two chiral carbons in C-6 were determined by degradation to be 3S4R.
1991, 2(10): 777-780
Abstract:
Deconjugation of cyclopent-2-enone aldols were attempted under various conditions, and the desired deconjugated product was achieved via dianion approach. Various results obtained in this study are explained by structure and transition state analysis.
Deconjugation of cyclopent-2-enone aldols were attempted under various conditions, and the desired deconjugated product was achieved via dianion approach. Various results obtained in this study are explained by structure and transition state analysis.
1991, 2(10): 781-782
Abstract:
The complex of [4Ni (salen)·GGH] CLO4·EtOH·H2O has been synthesized and studied by X-ray single crystal analysis. The results show that there are both intra-unit hydrogen bonds in the [4Ni (salen)·GGH]+ and inter-unit hydrogen bonds between the two [4Ni (salen)·GGH]+. Ni (salen) in the unit are still centrosymmetric dimers with planar structure. Imide N(10)-H(10) in the [GGH]+ bonds with one phenolic oxygen 0(7) of Ni (salen) dimer in the same unit. Two H atoms of amino group N (9)-H[H (A), H (C)] in the glycylglycine perchlorate interact with phenolic oxygen[0 (3), 0 (5)] of [4Ni (salen)·GGH]+ through two strong hydrogen bonds respectively.
The complex of [4Ni (salen)·GGH] CLO4·EtOH·H2O has been synthesized and studied by X-ray single crystal analysis. The results show that there are both intra-unit hydrogen bonds in the [4Ni (salen)·GGH]+ and inter-unit hydrogen bonds between the two [4Ni (salen)·GGH]+. Ni (salen) in the unit are still centrosymmetric dimers with planar structure. Imide N(10)-H(10) in the [GGH]+ bonds with one phenolic oxygen 0(7) of Ni (salen) dimer in the same unit. Two H atoms of amino group N (9)-H[H (A), H (C)] in the glycylglycine perchlorate interact with phenolic oxygen[0 (3), 0 (5)] of [4Ni (salen)·GGH]+ through two strong hydrogen bonds respectively.
1991, 2(10): 783-784
Abstract:
By means of the energy level formula E (p)=α+2βcos (pπ/(n+t+1)). the pseudo π ionization potentials of H-(CH2)n-X (X=H, F, Cl, Br, I, OH, and SH) are identified by optimizing linear regression analysis, from which α=13.54±0.50eV and β=1.75±0.13eV are obtained.
By means of the energy level formula E (p)=α+2βcos (pπ/(n+t+1)). the pseudo π ionization potentials of H-(CH2)n-X (X=H, F, Cl, Br, I, OH, and SH) are identified by optimizing linear regression analysis, from which α=13.54±0.50eV and β=1.75±0.13eV are obtained.
1991, 2(10): 785-786
Abstract:
A rare nor-sesquiterpenoid with a γ-spirolactone, pathyiactone A (1), was isolated from the soft coral Paralemnalia thysoides. The structure and absolute stereochemistry of 1 was established by spectral analysis, especially 2D NMR and difference NOE studies, and CD method.
A rare nor-sesquiterpenoid with a γ-spirolactone, pathyiactone A (1), was isolated from the soft coral Paralemnalia thysoides. The structure and absolute stereochemistry of 1 was established by spectral analysis, especially 2D NMR and difference NOE studies, and CD method.
1991, 2(10): 787-788
Abstract:
A new aporphine alkaloid, named fuzitine, was isolated from the tuber of Aconitum carmicheali Debx, and its chemical structure was established'on the basis of spectral analysis and chemical reaction.
A new aporphine alkaloid, named fuzitine, was isolated from the tuber of Aconitum carmicheali Debx, and its chemical structure was established'on the basis of spectral analysis and chemical reaction.
1991, 2(10): 789-792
Abstract:
A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)-meso-tetrakis-(4-N-trimethylammonium phenyl) porphine [T (4TMAP) P] complex. In the presence of Cd (Ⅱ), Bi (Ⅲ) reacts almost instantaneously with T (4TMAP) P in a 0. 6 mol/l NaAc-HAC buffer (PH5.8) at room temperature. The composition of the complex is T (4TMAP) P:Bi=1:1. The absorbance complex obeys Beer's law over the Bi (Ⅲ) concentration range 0.1-1.4 μg/ml. The linear relative coefficient γ is 0.9998. The apparent molar absorptivity was 1.75×105 1.mol-1. cm-1 at 463nm. The relative standard deviation of the method is 1.50% for Bi (Ⅲ) 7ug/10ml (10 determinations). The interference of foreign ions has been examined. This simple and rapid method can be applied to the assay of Bi (Ⅲ) in some tablets directly.
A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)-meso-tetrakis-(4-N-trimethylammonium phenyl) porphine [T (4TMAP) P] complex. In the presence of Cd (Ⅱ), Bi (Ⅲ) reacts almost instantaneously with T (4TMAP) P in a 0. 6 mol/l NaAc-HAC buffer (PH5.8) at room temperature. The composition of the complex is T (4TMAP) P:Bi=1:1. The absorbance complex obeys Beer's law over the Bi (Ⅲ) concentration range 0.1-1.4 μg/ml. The linear relative coefficient γ is 0.9998. The apparent molar absorptivity was 1.75×105 1.mol-1. cm-1 at 463nm. The relative standard deviation of the method is 1.50% for Bi (Ⅲ) 7ug/10ml (10 determinations). The interference of foreign ions has been examined. This simple and rapid method can be applied to the assay of Bi (Ⅲ) in some tablets directly.
1991, 2(10): 793-796
Abstract:
An easy-to-make ozone generator which can be made with readily available materials is proposed. Concentration of the ozone prepared with this generator could reach that of ozone in equilibrium with oxygen. Cured with the ozone thus prepared, GC capillary columns with immobilized SE-54 phase and excellent chromatographic performance were successfully prepared.
An easy-to-make ozone generator which can be made with readily available materials is proposed. Concentration of the ozone prepared with this generator could reach that of ozone in equilibrium with oxygen. Cured with the ozone thus prepared, GC capillary columns with immobilized SE-54 phase and excellent chromatographic performance were successfully prepared.
1991, 2(10): 797-800
Abstract:
It has been found that phenyl cobalt tetraphenylporphyrin (C6H5Cotpp) was formed when cobalt tetraphenylporphyrin (Cotpp) and benzene were introduced into the ion source of mass spectrometer, the mass spectra of Cotpp and C6H5Cotpp are discussed.
It has been found that phenyl cobalt tetraphenylporphyrin (C6H5Cotpp) was formed when cobalt tetraphenylporphyrin (Cotpp) and benzene were introduced into the ion source of mass spectrometer, the mass spectra of Cotpp and C6H5Cotpp are discussed.
1991, 2(10): 801-802
Abstract:
MnC24H27F12N7O3P2·C2H5OH, Mr-852, orthogonal, space group P21 3, a=15.220 (2)Å;Z=4; V=3525 (1)Å3; F (000)=1732; Dc=1.61g/cm3; μ=5.52cm-1 (Mo Kα=0.71073Å). Manganese (Ⅱ) atom is seven-coordinated, with the coordination polyhedron of a monocapped antitrigonal prism.
MnC24H27F12N7O3P2·C2H5OH, Mr-852, orthogonal, space group P21 3, a=15.220 (2)Å;Z=4; V=3525 (1)Å3; F (000)=1732; Dc=1.61g/cm3; μ=5.52cm-1 (Mo Kα=0.71073Å). Manganese (Ⅱ) atom is seven-coordinated, with the coordination polyhedron of a monocapped antitrigonal prism.
1991, 2(10): 803-804
Abstract:
The single crystal of two-electron heteropoly blue with Si as the heteroatom and α-Keggin structure K2H4SiMoⅤ2Mo (Ⅵ) 10O40·12H2O was obtained by electrolytic reduction. It crystallizes in a triclinic system with space group P1, Mr=2117.73, a=13.702 (4), b=14.107 (3), c=14.184 (2)Å; α=119.27 (1), β=93.14 (2),;γ=110. 3 (2)°, V=2154.29Å3, Z=2, F (000)=1999, μ=36.39cm-1, Dc=3.26 g/cm3. Final R factor is 0.0515. Mo (Ⅴ) is situated in two different edge-shared Mo3O13 groups. The heteropoly blue was characterized by IR, UV, polarography, X-ray photoelectron spectra and ESR. All the results show that the structure of the heteropoly anion with Keggin structure remains unchanged basically in the process of reduction.
The single crystal of two-electron heteropoly blue with Si as the heteroatom and α-Keggin structure K2H4SiMoⅤ2Mo (Ⅵ) 10O40·12H2O was obtained by electrolytic reduction. It crystallizes in a triclinic system with space group P1, Mr=2117.73, a=13.702 (4), b=14.107 (3), c=14.184 (2)Å; α=119.27 (1), β=93.14 (2),;γ=110. 3 (2)°, V=2154.29Å3, Z=2, F (000)=1999, μ=36.39cm-1, Dc=3.26 g/cm3. Final R factor is 0.0515. Mo (Ⅴ) is situated in two different edge-shared Mo3O13 groups. The heteropoly blue was characterized by IR, UV, polarography, X-ray photoelectron spectra and ESR. All the results show that the structure of the heteropoly anion with Keggin structure remains unchanged basically in the process of reduction.
1991, 2(10): 805-808
Abstract:
A flmorimetric method for determination of typtophan was proposed. This method is very simple, rapid in determination of tryptophan in aqueous medium. The percentage of recovery was satisfactory.
A flmorimetric method for determination of typtophan was proposed. This method is very simple, rapid in determination of tryptophan in aqueous medium. The percentage of recovery was satisfactory.
1991, 2(10): 809-812
Abstract:
Mothod (SA) was applied to the conformational analysis of flexible molecules such as peptides. The programs SAMM and SAPEP have been developed, using MM2 force field for organic molecules and ECEPP/2 force field for peptides respectively.nte-Carlo simulated annealing me
Mothod (SA) was applied to the conformational analysis of flexible molecules such as peptides. The programs SAMM and SAPEP have been developed, using MM2 force field for organic molecules and ECEPP/2 force field for peptides respectively.nte-Carlo simulated annealing me
1991, 2(10): 813-816
Abstract:
A newly proposed ESAg concept is verified by the coaggregation behavior of an anionic kinetic probe (P16-) with various surfactants.
A newly proposed ESAg concept is verified by the coaggregation behavior of an anionic kinetic probe (P16-) with various surfactants.
1991, 2(10): 817-820
Abstract:
A novel amphiphile of 4-[4-(4-decyloxyphenylazo) naphthyloxy] butyl trimethylammonium bromide has been synthesized. It can form the stable bilayer in dilute aqueous solution.
A novel amphiphile of 4-[4-(4-decyloxyphenylazo) naphthyloxy] butyl trimethylammonium bromide has been synthesized. It can form the stable bilayer in dilute aqueous solution.
1991, 2(10): 821-822
Abstract:
Induction-Polymerization is a novel method for preparing polymers of regular structure. In the presence of a special macromolecular compound, monomer molecules are aggregeted regularly around one or more growth points and polymerized to polymer of regular structure. Regularity of structure of the polyacrylamide prepared by this means has been verified with electron diffractograms, DSC curve and IR spectrum of the polymer.
Induction-Polymerization is a novel method for preparing polymers of regular structure. In the presence of a special macromolecular compound, monomer molecules are aggregeted regularly around one or more growth points and polymerized to polymer of regular structure. Regularity of structure of the polyacrylamide prepared by this means has been verified with electron diffractograms, DSC curve and IR spectrum of the polymer.
1991, 2(10): 823-826
Abstract:
The in vitro effects of baicalein,wogonin,baicalin and Na2MoO4 on N-nitrosation reaction have been studied. The N-nitrosation reaction has been determined by the amount of dimethylnitrosamine (DMN) and diethylnitrosamine (DEN) produced using the UV-photclysis spectrophotometric and pyrolysis gas chromatography test. Baicalein,wogonin and Na2MoO4 showed varing extents of inhibition of the formation of DMN and DEN. Baicalin promoted the formation of DMN and DEN under the condition of simulating gastric Juices. It is also found that E. coli showed a remarkable promoting effect on the formation of DMN and DEN,but this promoting effect could be blocked to some extent by baicalein,wogonin,baicalin and Na2MoO4. Besides, Na2MoO4 and wogonin have shown synergic effect on the blocking of N-nitrosation reaction.
The in vitro effects of baicalein,wogonin,baicalin and Na2MoO4 on N-nitrosation reaction have been studied. The N-nitrosation reaction has been determined by the amount of dimethylnitrosamine (DMN) and diethylnitrosamine (DEN) produced using the UV-photclysis spectrophotometric and pyrolysis gas chromatography test. Baicalein,wogonin and Na2MoO4 showed varing extents of inhibition of the formation of DMN and DEN. Baicalin promoted the formation of DMN and DEN under the condition of simulating gastric Juices. It is also found that E. coli showed a remarkable promoting effect on the formation of DMN and DEN,but this promoting effect could be blocked to some extent by baicalein,wogonin,baicalin and Na2MoO4. Besides, Na2MoO4 and wogonin have shown synergic effect on the blocking of N-nitrosation reaction.
1991, 2(10): 827-828
Abstract:
Superoxide ion O2- is prepared in aprotic media by carbon gas-diffusion-electrode for the first time. The experimental results indicate that this electrode is superior to carbon plane-electrode in the reaction of O2- with p-bromonitrobenzene. When the gas-diffussion-electrode is used, the yield of the product nitrophenol increases by 20%, and the selectivity of the reaction is nearly doubled as compared with the plane-electrode.
Superoxide ion O2- is prepared in aprotic media by carbon gas-diffusion-electrode for the first time. The experimental results indicate that this electrode is superior to carbon plane-electrode in the reaction of O2- with p-bromonitrobenzene. When the gas-diffussion-electrode is used, the yield of the product nitrophenol increases by 20%, and the selectivity of the reaction is nearly doubled as compared with the plane-electrode.
