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1997 Volume 8 Issue 7
1997, 8(7): 559-562
Abstract:
Several cyclopropanation catalysts for the synthesis of 3 (2,2-dichlorovinyl)-2,2.dimethylcyclopropanecarboxylates have been studied in this paper.Owing to electron deficiency of 1,1-dichloro-4-methyl-1,3-pentadiene,yield of this reaction is rather low compared with that of 2,5-dimethyl-2,4-pentadiene.Of all catalysts concerned,yield ranged from 25.1% to 47.2%.
Several cyclopropanation catalysts for the synthesis of 3 (2,2-dichlorovinyl)-2,2.dimethylcyclopropanecarboxylates have been studied in this paper.Owing to electron deficiency of 1,1-dichloro-4-methyl-1,3-pentadiene,yield of this reaction is rather low compared with that of 2,5-dimethyl-2,4-pentadiene.Of all catalysts concerned,yield ranged from 25.1% to 47.2%.
1997, 8(7): 563-564
Abstract:
The [4+3] cycloaddition of the 6-substituted-2-chlorocyclohexanone and furans under the Fohlish conditions (Et3N in CF3CH3OH) has been accomplished to give tricyclic cycloadducts with good yields.
The [4+3] cycloaddition of the 6-substituted-2-chlorocyclohexanone and furans under the Fohlish conditions (Et3N in CF3CH3OH) has been accomplished to give tricyclic cycloadducts with good yields.
1997, 8(7): 565-568
Abstract:
In the presence of CrCl3/Fe bimetal couple,per(poly) fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.
In the presence of CrCl3/Fe bimetal couple,per(poly) fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.
1997, 8(7): 569-572
Abstract:
A series of new Schiff base type macrocyclic crown ethers containing naphthalene ring were synthesized from 2,2'-di(o-formylnaphthoxy) ethyl ether or 1,2-di(o-formylnaphthoxy)ethane and four appropriate diamines.The chemical structures of the new compounds were characterized by elemental analysis,infrared spectra,nuclear magnetic resonance spectra and mass spectrometry.
A series of new Schiff base type macrocyclic crown ethers containing naphthalene ring were synthesized from 2,2'-di(o-formylnaphthoxy) ethyl ether or 1,2-di(o-formylnaphthoxy)ethane and four appropriate diamines.The chemical structures of the new compounds were characterized by elemental analysis,infrared spectra,nuclear magnetic resonance spectra and mass spectrometry.
1997, 8(7): 573-576
Abstract:
The thiono-thiolo allylic rearrangement of O-allyl-O-aryl-O-ethyl thionophosphates(1a-j) adsorbed on SiO2 afforded the corresponding O-aryl-O-ethyl-S-allyl thiolophosphates (2a-j) in good yields.
The thiono-thiolo allylic rearrangement of O-allyl-O-aryl-O-ethyl thionophosphates(1a-j) adsorbed on SiO2 afforded the corresponding O-aryl-O-ethyl-S-allyl thiolophosphates (2a-j) in good yields.
1997, 8(7): 577-578
Abstract:
4-(1-Pyrrolyl) butanenitrile (4),the key intermediate for the synthesis of 1,2,3,4-tetrahydro-1-indolizinone,was prepared with Clauson-Kass reation.When pyrrole reacted with 4-bromobutanenitrile in PEG-400 dimethyl ether catalyzed by NaOH,3-(1-pyrrolyl) butanenitrile was obtained.The nitrites were converted into the corresponding ketones by Hoesch reaction.Some of the ketone derivatives were prepared.
4-(1-Pyrrolyl) butanenitrile (4),the key intermediate for the synthesis of 1,2,3,4-tetrahydro-1-indolizinone,was prepared with Clauson-Kass reation.When pyrrole reacted with 4-bromobutanenitrile in PEG-400 dimethyl ether catalyzed by NaOH,3-(1-pyrrolyl) butanenitrile was obtained.The nitrites were converted into the corresponding ketones by Hoesch reaction.Some of the ketone derivatives were prepared.
1997, 8(7): 579-582
Abstract:
5-1',1'-dimethylundecenyloxyphenylmethyl-11,17,23-tris-1",1"-dimethylethyl-25,26,27,28-tetrahydroxycalix [4] arene was synthesized from 1,1-dimethylundecenyoxylphenyl-methylphenol (3) and bishydroxymethylated p-tert-butylphenol-formaldehyde trimer (7) (3-[3-[3-(Hydroxymethyl)-5-tert-butylsalicyl-5]-tert-butylsalicy]-5-tert-butyl-2-hydroxybenzyl Alcohol) by ‘1+3’ fragment condensation in dioxane with TiCl4 as condensation agent in 28% yield.It is the first long-chain monoalkenyl substituted calix [4] arene in which the alkenyl was attached to the upper rim of calix [4] arene.
5-1',1'-dimethylundecenyloxyphenylmethyl-11,17,23-tris-1",1"-dimethylethyl-25,26,27,28-tetrahydroxycalix [4] arene was synthesized from 1,1-dimethylundecenyoxylphenyl-methylphenol (3) and bishydroxymethylated p-tert-butylphenol-formaldehyde trimer (7) (3-[3-[3-(Hydroxymethyl)-5-tert-butylsalicyl-5]-tert-butylsalicy]-5-tert-butyl-2-hydroxybenzyl Alcohol) by ‘1+3’ fragment condensation in dioxane with TiCl4 as condensation agent in 28% yield.It is the first long-chain monoalkenyl substituted calix [4] arene in which the alkenyl was attached to the upper rim of calix [4] arene.
1997, 8(7): 583-586
Abstract:
Ethyl α-(2-alkenyl)-α-perfluoroacylacetates (4) are synthesized from the reaction of ethyl α-perfluoroalkylacetates with allylic alcohols in the presence of the mixed base of triethylamine and sodium dicarbonate.lodoenoletherification of the compounds 4 afforded 2-fluoroalkylated tetrahvdrofuran derivatives 5 under the improved conditions.The possible reaction pathways are suggested.
Ethyl α-(2-alkenyl)-α-perfluoroacylacetates (4) are synthesized from the reaction of ethyl α-perfluoroalkylacetates with allylic alcohols in the presence of the mixed base of triethylamine and sodium dicarbonate.lodoenoletherification of the compounds 4 afforded 2-fluoroalkylated tetrahvdrofuran derivatives 5 under the improved conditions.The possible reaction pathways are suggested.
1997, 8(7): 587-590
Abstract:
Some novel polypyridine ligands containing adsorbing groups were synthesized with the purpose of developing new ruthenium(Ⅱ) polypyridine complexes to be used in solar cell based on dye-sensitized nanocrystilline TiO2 film electrode.
Some novel polypyridine ligands containing adsorbing groups were synthesized with the purpose of developing new ruthenium(Ⅱ) polypyridine complexes to be used in solar cell based on dye-sensitized nanocrystilline TiO2 film electrode.
1997, 8(7): 591-594
Abstract:
A concise synthesis of naturally occurring S-(-)-zearalenone has been described.
A concise synthesis of naturally occurring S-(-)-zearalenone has been described.
1997, 8(7): 595-598
Abstract:
The first total synthesis of five linear diterpenes:eleganolone (1),eleganolone acetate (2),elegandiol (3),eleganonal (4) and epoxyeleganolone (5),was achieved from (E,E)-farnesol (6) via 4 to 6 steps.The key step was the alkylation reaction of silyl cyanide with allylic iodide.
The first total synthesis of five linear diterpenes:eleganolone (1),eleganolone acetate (2),elegandiol (3),eleganonal (4) and epoxyeleganolone (5),was achieved from (E,E)-farnesol (6) via 4 to 6 steps.The key step was the alkylation reaction of silyl cyanide with allylic iodide.
1997, 8(7): 599-602
Abstract:
Five new flavonoids were isolated from the aerial parts of Bidens pilosa L.var.vadiata Sch.-Bip..Their structures were established on the basis of spectroscopic methods.
Five new flavonoids were isolated from the aerial parts of Bidens pilosa L.var.vadiata Sch.-Bip..Their structures were established on the basis of spectroscopic methods.
1997, 8(7): 603-606
Abstract:
Four new diterpenoids named maoecrystal Q-T (1-4) were isolated from the dried leaves of Isodon eriocalyx.Their sturctures were established by spectroscopic methods.
Four new diterpenoids named maoecrystal Q-T (1-4) were isolated from the dried leaves of Isodon eriocalyx.Their sturctures were established by spectroscopic methods.
1997, 8(7): 607-610
Abstract:
A new basic dodecapeptide BPP was isolated from the water-extract of the buckwheat pollen (BP).The sequence of BPP,which was first reported,was determined by DABITC/PITC double coupling method,and confirmed by chemical synthesis.Some analogues of BPP were also synthesized by SPPS Method.The effect of these peptides on spleen lymphocytes from mice of Kunming inbred line and on release of SIL-2R from human lymphocytes were studied.The results showed that these peptides exhibit certain immune activity.
A new basic dodecapeptide BPP was isolated from the water-extract of the buckwheat pollen (BP).The sequence of BPP,which was first reported,was determined by DABITC/PITC double coupling method,and confirmed by chemical synthesis.Some analogues of BPP were also synthesized by SPPS Method.The effect of these peptides on spleen lymphocytes from mice of Kunming inbred line and on release of SIL-2R from human lymphocytes were studied.The results showed that these peptides exhibit certain immune activity.
1997, 8(7): 611-612
Abstract:
The cleavage reactions of Ser-His and its N-terminal phosphorylated form-N-(O,O-diisopropyl) phosphoryl seryl-histidine (DIPP-Ser-His) were studied on DNA.It was found that the phosphorylation of Ser-His caused the lost of the cleavage activity on DNA.The result might give some clue on the regulation of the activity of protein by phosphorylation.
The cleavage reactions of Ser-His and its N-terminal phosphorylated form-N-(O,O-diisopropyl) phosphoryl seryl-histidine (DIPP-Ser-His) were studied on DNA.It was found that the phosphorylation of Ser-His caused the lost of the cleavage activity on DNA.The result might give some clue on the regulation of the activity of protein by phosphorylation.
1997, 8(7): 613-614
Abstract:
Heptakis (2,3,6-tri-o-n-butyl)-β-cyclodextrin (TB-β-CD) has been found to form an inclusion compound with p-nitrophenol in heptane.The stability constant of the inclusion compound of p-nitrophenol with TB-β-CD in heptane is an order of magnitude greater than that in water.
Heptakis (2,3,6-tri-o-n-butyl)-β-cyclodextrin (TB-β-CD) has been found to form an inclusion compound with p-nitrophenol in heptane.The stability constant of the inclusion compound of p-nitrophenol with TB-β-CD in heptane is an order of magnitude greater than that in water.
1997, 8(7): 615-618
Abstract:
A modified two-stage soft-docking procedure was developed for the theoretic researches on the recognition of protein-protein or protein-peptide complexes.Some systems have been used to test our program and the results are encouraging.
A modified two-stage soft-docking procedure was developed for the theoretic researches on the recognition of protein-protein or protein-peptide complexes.Some systems have been used to test our program and the results are encouraging.
1997, 8(7): 619-622
Abstract:
A micellar electrokinetic chromatographic (MECC) method with sodium cholate as pseudostationary phase was proposed for the separation and quantitation of two analgesic formulations containing acetaminophen,dextro-methorphan hydrobromide,phenylpropanolamine hydrochloride,and chlorpheniramine maleate.The internal standard method was proved to be able to yield satisfactory results even with a modular CE instrument with RSD between 0.6~2.1%,and recoveries ranging from 98.1~99.9%.
A micellar electrokinetic chromatographic (MECC) method with sodium cholate as pseudostationary phase was proposed for the separation and quantitation of two analgesic formulations containing acetaminophen,dextro-methorphan hydrobromide,phenylpropanolamine hydrochloride,and chlorpheniramine maleate.The internal standard method was proved to be able to yield satisfactory results even with a modular CE instrument with RSD between 0.6~2.1%,and recoveries ranging from 98.1~99.9%.
1997, 8(7): 623-626
Abstract:
An array composed of sixteen gas sensors was constructed to analyze gas mixtures quantitatively.The data of responses from the sensor array to ethane,propane and propylene were treated by three-layer ANN with BP algorithms and PLS.The analytical results indicated that the concentration predicted with ANN is better than that with PLS.The average prediction errors for ethane,propane and propylene were 5.11%,8.28%,2.64%,respectively.
An array composed of sixteen gas sensors was constructed to analyze gas mixtures quantitatively.The data of responses from the sensor array to ethane,propane and propylene were treated by three-layer ANN with BP algorithms and PLS.The analytical results indicated that the concentration predicted with ANN is better than that with PLS.The average prediction errors for ethane,propane and propylene were 5.11%,8.28%,2.64%,respectively.
1997, 8(7): 627-628
Abstract:
In the media of 0.66,0.96,2.16 and 0.54 mol/L of H2SO4,the heteropoly acids of As,P,Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin,which exhibit maximum absorptions at 835,820,810 and 805 nm with molar absorptivities of 2.64×104,2.54×104,3.51×104 and 2.25×104 L·mol-1·cm-1 and linear ranges of 0-30,0-15,0-10 and 0-30 μg/25mL,respectively.The method was applied to the determinations of As,P and Si in alloyed steel.
In the media of 0.66,0.96,2.16 and 0.54 mol/L of H2SO4,the heteropoly acids of As,P,Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin,which exhibit maximum absorptions at 835,820,810 and 805 nm with molar absorptivities of 2.64×104,2.54×104,3.51×104 and 2.25×104 L·mol-1·cm-1 and linear ranges of 0-30,0-15,0-10 and 0-30 μg/25mL,respectively.The method was applied to the determinations of As,P and Si in alloyed steel.
1997, 8(7): 629-632
Abstract:
The electron impact ionization mass spectral fragmentations of a series of acylaminotetraoxyphosphoranes were investigated.The results showed that EIMS of such compounds exhibited very characteristic fragmentation patterns,which would provide useful clues for the structural assignment of this type of compounds.
The electron impact ionization mass spectral fragmentations of a series of acylaminotetraoxyphosphoranes were investigated.The results showed that EIMS of such compounds exhibited very characteristic fragmentation patterns,which would provide useful clues for the structural assignment of this type of compounds.
1997, 8(7): 633-636
Abstract:
Ternary complexes of terbium with ortho (and para) aminobenzoic acid and 1,10-phenanthroline were introduced into silica gel by the sol-gel method.The luminescence behavior of the solid-state samples was studied during the sol-gel aging process by means of emission,excitation spectra,lifetimes and quantum efficiencies.
Ternary complexes of terbium with ortho (and para) aminobenzoic acid and 1,10-phenanthroline were introduced into silica gel by the sol-gel method.The luminescence behavior of the solid-state samples was studied during the sol-gel aging process by means of emission,excitation spectra,lifetimes and quantum efficiencies.
1997, 8(7): 637-638
Abstract:
It was first found that diisopropylamido bis(methylcyclopentadienyl) ytterbium complex (MeCp)2YbN(i-Pr)2(THF) exhibits extremely high catalytic activity in the polymerization of methyl methacrylate.The reactions can be carried out over a quite broad range of polymerization temperatures from-78℃ to 40℃.The results of GPC (gel permeation chromatography) indicate that the molecular weight distribution (Mw/Mn) becomes broad with the increase of temperature.
It was first found that diisopropylamido bis(methylcyclopentadienyl) ytterbium complex (MeCp)2YbN(i-Pr)2(THF) exhibits extremely high catalytic activity in the polymerization of methyl methacrylate.The reactions can be carried out over a quite broad range of polymerization temperatures from-78℃ to 40℃.The results of GPC (gel permeation chromatography) indicate that the molecular weight distribution (Mw/Mn) becomes broad with the increase of temperature.
1997, 8(7): 639-640
Abstract:
Phenyl isocyanate was for the first time successfully polymerized by divalent samarium complex (ArO)2Sm(THF)4.The monomer concentration and temperature affected the polymerization greatly.
Phenyl isocyanate was for the first time successfully polymerized by divalent samarium complex (ArO)2Sm(THF)4.The monomer concentration and temperature affected the polymerization greatly.
1997, 8(7): 641-642
Abstract:
Tb(Ⅲ) and Ca(Ⅱ) ion equilibria in the presence of glutamic acid and glutamine were studied by potentiometric titration at 37℃ and an ionic strength of 0.15mol/L(NaCl).The stability constants for Tb(Ⅲ) and Ca(Ⅱ) complexes in the systems were obtained.The species and their distribution in the systems were discussed.
Tb(Ⅲ) and Ca(Ⅱ) ion equilibria in the presence of glutamic acid and glutamine were studied by potentiometric titration at 37℃ and an ionic strength of 0.15mol/L(NaCl).The stability constants for Tb(Ⅲ) and Ca(Ⅱ) complexes in the systems were obtained.The species and their distribution in the systems were discussed.
1997, 8(7): 643-644
Abstract:
The investigation of the system BaF2-WO3 revealed the existence of a fluoro-tungstate formulated as Ba2WO3F4.The Ba2WO3F4 was prepared with the solid state reaction method.Under UV or X-ray excitation,Ba2WO3F4 exhibits a very strong blue-green emission peaking at 480 nm at room temperature.The luminescence properties are similar to those of the tungstate,especially MgWO4.
The investigation of the system BaF2-WO3 revealed the existence of a fluoro-tungstate formulated as Ba2WO3F4.The Ba2WO3F4 was prepared with the solid state reaction method.Under UV or X-ray excitation,Ba2WO3F4 exhibits a very strong blue-green emission peaking at 480 nm at room temperature.The luminescence properties are similar to those of the tungstate,especially MgWO4.
1997, 8(7): 645-646
Abstract:
Ab initio potential surface of oxidative addition of CH4 to coordinatively unsaturated PtCl2 is presented.The electron correlation has a big effect on the transition state and activation energy.
Ab initio potential surface of oxidative addition of CH4 to coordinatively unsaturated PtCl2 is presented.The electron correlation has a big effect on the transition state and activation energy.
1997, 8(7): 647-648
Abstract:
The crystal structure of [Co(NH3)5Br]Br2 has been determined ab initio from the conventional X-ray powder diffraction data.The approximate structure with all 7 independent non-H atoms was solved by direct methods.The final orthorhombic unit-cell parameters after Rietveld refinement are:a=13.6927,b=10.7071,c=6.9400Å,V=1017.47Å3,F30=93(0.0075,43),M20=49,Z=4.Space group is Pnma.The structure agreement factors are:Rp=0.066,Rwp=0.090,RF=0.041,RB=0.042.
The crystal structure of [Co(NH3)5Br]Br2 has been determined ab initio from the conventional X-ray powder diffraction data.The approximate structure with all 7 independent non-H atoms was solved by direct methods.The final orthorhombic unit-cell parameters after Rietveld refinement are:a=13.6927,b=10.7071,c=6.9400Å,V=1017.47Å3,F30=93(0.0075,43),M20=49,Z=4.Space group is Pnma.The structure agreement factors are:Rp=0.066,Rwp=0.090,RF=0.041,RB=0.042.
1997, 8(7): 649-652
Abstract:
Mesoporous molecular sieve MCM-41 has been synthesized in the extremely dense system (with H2O/Si < 10) and characterized by XRD,N2 adsorption isotherm as well as probe reactions of cracking of cumene and isomerization of o-xylene.
Mesoporous molecular sieve MCM-41 has been synthesized in the extremely dense system (with H2O/Si < 10) and characterized by XRD,N2 adsorption isotherm as well as probe reactions of cracking of cumene and isomerization of o-xylene.
