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2000 Volume 11 Issue 4
α-Oxo Ketene Dithioacetals Chemistry-A Facile Route to the Synthesis of Fused Heterocyclic Compounds
2000, 11(4): 283-284
Abstract:
The fused heterocyclic compounds 2:imidazo[1,2-a] pyridine 2a-c and pyrido[1,2-a] pyrimidine 2d were obtained from the reaction of α-cinnamoyl ketene dibenzylthio acetals 1 with diamine. When α-cinnamoyl-α'-benzoyl ketene N, N-acetals 3a-b were treated by t-BuONa/t-BuOH solution, 8-benzoyl-pyrido[1,2-a] pyrimidine 4 was produced.
The fused heterocyclic compounds 2:imidazo[1,2-a] pyridine 2a-c and pyrido[1,2-a] pyrimidine 2d were obtained from the reaction of α-cinnamoyl ketene dibenzylthio acetals 1 with diamine. When α-cinnamoyl-α'-benzoyl ketene N, N-acetals 3a-b were treated by t-BuONa/t-BuOH solution, 8-benzoyl-pyrido[1,2-a] pyrimidine 4 was produced.
2000, 11(4): 285-288
Abstract:
The intra-molecular addition reaction of Grignard reagent with quaternary C=N bond of benzimidazole methiodide salt is reported, and a novel method for the synthesis of cycloundecanone is provided.
The intra-molecular addition reaction of Grignard reagent with quaternary C=N bond of benzimidazole methiodide salt is reported, and a novel method for the synthesis of cycloundecanone is provided.
2000, 11(4): 289-292
Abstract:
the reaction of C60 with methyl bromoacetate in the presence of SmI2 gives the title compound 1-methoxycarbonylmethyl-2-hydrofullerene in good yield.
the reaction of C60 with methyl bromoacetate in the presence of SmI2 gives the title compound 1-methoxycarbonylmethyl-2-hydrofullerene in good yield.
2000, 11(4): 293-294
Abstract:
α-Seleno arsonium ylides 5 have been synthesized through the reaction of α-unfunctionalized arsonium ylides 4 with almost equimolar phenylselenenyl iodide 2.
α-Seleno arsonium ylides 5 have been synthesized through the reaction of α-unfunctionalized arsonium ylides 4 with almost equimolar phenylselenenyl iodide 2.
2000, 11(4): 295-296
Abstract:
C2a-β-H ketone 6 was synthesized from the exo-IMDA-additive 4 with the aid of singlet oxygen, and ring E of hainanolide was assembled via kinetic enol ether of 6.
C2a-β-H ketone 6 was synthesized from the exo-IMDA-additive 4 with the aid of singlet oxygen, and ring E of hainanolide was assembled via kinetic enol ether of 6.
2000, 11(4): 297-300
Abstract:
Carbobenzoxy-L-3,3,3-trifluoroalanine was synthesized and it was incorporated into MDP for replacement of L-alanine.
Carbobenzoxy-L-3,3,3-trifluoroalanine was synthesized and it was incorporated into MDP for replacement of L-alanine.
2000, 11(4): 301-304
Abstract:
14-Nor-3-oxodihydroagarofuran (2) was prepared in high yield. From 2, derivatives 12 and 13 were synthesized by Grignard addition. In order to identify the configuration of C-3 in compound 12 and 13, the sterospecific synthesis of compound 12 has been carried out in 5 steps from octalone (14).
14-Nor-3-oxodihydroagarofuran (2) was prepared in high yield. From 2, derivatives 12 and 13 were synthesized by Grignard addition. In order to identify the configuration of C-3 in compound 12 and 13, the sterospecific synthesis of compound 12 has been carried out in 5 steps from octalone (14).
2000, 11(4): 305-306
Abstract:
A kind of novel electroluminescence polymer has been prepared by oxidative-coupling polymerization of N-alkyl carbazole and trans-stilbene. The structure of the copolymers was characterized by elemental analysis, UV-vis and FTIR spectra. The copolymers have good solubility in chloroform and acetone. Fluorescence spectra showed that these polymers are blue-light emitting materials.
A kind of novel electroluminescence polymer has been prepared by oxidative-coupling polymerization of N-alkyl carbazole and trans-stilbene. The structure of the copolymers was characterized by elemental analysis, UV-vis and FTIR spectra. The copolymers have good solubility in chloroform and acetone. Fluorescence spectra showed that these polymers are blue-light emitting materials.
2000, 11(4): 307-310
Abstract:
Two novel heterocyclic diamine monomers:1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-amin-ophenoxy)phenyl](2H)phthalazin-1-one and 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-3,5-dimethylphenyl](2H)phthalazin-1-one were successfully synthesized from readily available heterocyclic bisphenol-like monomers in two steps in high yield. A series of novel poly (aryl ether amide)s containing the phthalazinone moiety were successfully prepared by the direct polymerization of the novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents.
Two novel heterocyclic diamine monomers:1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-amin-ophenoxy)phenyl](2H)phthalazin-1-one and 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-3,5-dimethylphenyl](2H)phthalazin-1-one were successfully synthesized from readily available heterocyclic bisphenol-like monomers in two steps in high yield. A series of novel poly (aryl ether amide)s containing the phthalazinone moiety were successfully prepared by the direct polymerization of the novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents.
2000, 11(4): 311-314
Abstract:
The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO4)2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 l h-1 g-cat-1, the CFC-12 conversion at 310℃ over Ti(SO4)2 calcined at 350℃ remained about 98.5% during 360 h on stream, and the selectivity to by-products remained zero. The findings enlarged the scope of traditional catalyst systems for the CFCs decomposition.
The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO4)2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 l h-1 g-cat-1, the CFC-12 conversion at 310℃ over Ti(SO4)2 calcined at 350℃ remained about 98.5% during 360 h on stream, and the selectivity to by-products remained zero. The findings enlarged the scope of traditional catalyst systems for the CFCs decomposition.
2000, 11(4): 315-318
Abstract:
Two new compounds named decuroside VI (1) and decursidate (2) were isolated from the roots of Peucedanum decursivum-a traditional Chinese medicine. Their structures were elucidated on the basis of chemical evidence and spectral analysis.
Two new compounds named decuroside VI (1) and decursidate (2) were isolated from the roots of Peucedanum decursivum-a traditional Chinese medicine. Their structures were elucidated on the basis of chemical evidence and spectral analysis.
2000, 11(4): 319-322
Abstract:
Two new iridoid glucosides were isolated from the whole plant of Caryopteris mongholica Bunge. On the basis of chemical and spectral evidence, they were determined as 8-acetyl-6'-O-(p-coumaroyl) harpagide and 6'-O-(p-coumaroyl) antirrinoside, respectively.
Two new iridoid glucosides were isolated from the whole plant of Caryopteris mongholica Bunge. On the basis of chemical and spectral evidence, they were determined as 8-acetyl-6'-O-(p-coumaroyl) harpagide and 6'-O-(p-coumaroyl) antirrinoside, respectively.
2000, 11(4): 323-326
Abstract:
A new phenylpropanoid glycoside, serratumoside A, was isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Its structure was determined by spectral and chemical methods.
A new phenylpropanoid glycoside, serratumoside A, was isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Its structure was determined by spectral and chemical methods.
2000, 11(4): 327-330
Abstract:
A new C21 furanoterpene, ent-untenospongin A (2), together with a known related compound, tetradehydrofurospongin-1 (1), has been isolated from the Indian marine sponge Hippospongia sp. and its structure was determined on the basis of spectroscopic data.
A new C21 furanoterpene, ent-untenospongin A (2), together with a known related compound, tetradehydrofurospongin-1 (1), has been isolated from the Indian marine sponge Hippospongia sp. and its structure was determined on the basis of spectroscopic data.
2000, 11(4): 331-332
Abstract:
Two new β-dihydroagarofuran sesquiterpenes were isolated from Euonymus phellomana Loes.and their structures were established on the basis of spectral analysis.
Two new β-dihydroagarofuran sesquiterpenes were isolated from Euonymus phellomana Loes.and their structures were established on the basis of spectral analysis.
2000, 11(4): 333-336
Abstract:
A new triterpenoid saponin, se-saponin A, was isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Its structure was determined by spectral and chemical methods. Only one triterpenoid saponin has been isolated from Clerodendrum genus before. Se-saponin A is the second instance.
A new triterpenoid saponin, se-saponin A, was isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Its structure was determined by spectral and chemical methods. Only one triterpenoid saponin has been isolated from Clerodendrum genus before. Se-saponin A is the second instance.
2000, 11(4): 337-340
Abstract:
A new triterpenoid saponin, together with a known saponin, was isolated from the flowers of Lonicera Japonica Thunb. Using chemical and spectroscopic methods, mainly 2D NMR technique, their structures were deduced to be 3-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→3)-α-L-rhamnospyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside and 3-α-L-rhamnospyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnospyranosyl-(1→2)-[β-D-xylcopyranosyl-(1→6)]-β-D-glucopyranoside, respectively.
A new triterpenoid saponin, together with a known saponin, was isolated from the flowers of Lonicera Japonica Thunb. Using chemical and spectroscopic methods, mainly 2D NMR technique, their structures were deduced to be 3-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→3)-α-L-rhamnospyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside and 3-α-L-rhamnospyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnospyranosyl-(1→2)-[β-D-xylcopyranosyl-(1→6)]-β-D-glucopyranoside, respectively.
2000, 11(4): 341-342
Abstract:
Calamistrin E, the first Annonaceous acetogenin with C=C bond in the aliphatic chain from the genus Uvaria was isolated from U. calamistrata. Its structure including relative and absolute configurations was determined by chemical derivation and spectral analysis.
Calamistrin E, the first Annonaceous acetogenin with C=C bond in the aliphatic chain from the genus Uvaria was isolated from U. calamistrata. Its structure including relative and absolute configurations was determined by chemical derivation and spectral analysis.
2000, 11(4): 343-346
Abstract:
From the radix of Pueraria peduncularis Grah., two new oleanene-type triterpenoid saponins named pedunsaponins B (2) and C (3) were isolated. Their structures were determined as 3-O-(6-O-methyl)-β-D-glucuronopyranosyl-3β,15α-diol-12-oleanene-16-one (2) and 3-O-β-D-glucopyranosyl-(1→3)-β-D-glucuronopyranosyl-3β,15α-diol-12-oleanene-16-one (3) on the basis of spectroscopic evidence and chemical reactions.
From the radix of Pueraria peduncularis Grah., two new oleanene-type triterpenoid saponins named pedunsaponins B (2) and C (3) were isolated. Their structures were determined as 3-O-(6-O-methyl)-β-D-glucuronopyranosyl-3β,15α-diol-12-oleanene-16-one (2) and 3-O-β-D-glucopyranosyl-(1→3)-β-D-glucuronopyranosyl-3β,15α-diol-12-oleanene-16-one (3) on the basis of spectroscopic evidence and chemical reactions.
2000, 11(4): 347-350
Abstract:
A molecular dynamic method in conjunction with a statistic test has been utilized to model chiral recognition of α-phenylethylamine on heptakis (2,6-di-O-butyl-3-O-butyryl)-β-cyclodextrin in gas chromatography. The modelling data correlated with the chromatographic elution order, and indicated that the preferred site of α-phenylethylamine is the interior of cavity.
A molecular dynamic method in conjunction with a statistic test has been utilized to model chiral recognition of α-phenylethylamine on heptakis (2,6-di-O-butyl-3-O-butyryl)-β-cyclodextrin in gas chromatography. The modelling data correlated with the chromatographic elution order, and indicated that the preferred site of α-phenylethylamine is the interior of cavity.
2000, 11(4): 351-352
Abstract:
A highly sensitive linear sweep voltammetric method was developed for the determination of paclitaxel and the mechanism of the binding of paclitaxel to tubulin was studied. Tubulin dimer formed with paclitaxel an electrochemically nonactive complex with a combination ratio of 2:2. Its stability constant was 2.85×1022. So the tubulin dimer had two binding sites for paclitaxel. The experiment showed that the binding sites of paclitaxel to tubulin dimer were different from that of Ca2+ to tubulin dimer.
A highly sensitive linear sweep voltammetric method was developed for the determination of paclitaxel and the mechanism of the binding of paclitaxel to tubulin was studied. Tubulin dimer formed with paclitaxel an electrochemically nonactive complex with a combination ratio of 2:2. Its stability constant was 2.85×1022. So the tubulin dimer had two binding sites for paclitaxel. The experiment showed that the binding sites of paclitaxel to tubulin dimer were different from that of Ca2+ to tubulin dimer.
2000, 11(4): 353-356
Abstract:
Excellent resolution of racemic 2-phenyl-1,1-cyclopropanedicarbonitrile and its nine analogues was accomplished using 100-5CHI-TBB chiral stationary phase under normal-phase HPLC conditions. The influence of mobile phase and the optimum conditions for the resolution of optically active enantiomers were investigated.
Excellent resolution of racemic 2-phenyl-1,1-cyclopropanedicarbonitrile and its nine analogues was accomplished using 100-5CHI-TBB chiral stationary phase under normal-phase HPLC conditions. The influence of mobile phase and the optimum conditions for the resolution of optically active enantiomers were investigated.
Removal of Endotoxin from Human Serum Albumin Solutions by Hydrophobic and Cationic Charged Membrane
2000, 11(4): 357-360
Abstract:
A novel matrix of macropore cellulose membrane was prepared by chemical graft, and immobilized the cationic charged groups as affinity ligands. The prepared membrane can be used for the removal of endotoxin from human serum albumin (HSA) solutions. With a cartridge of 20 sheets affinity membrane of 47 mm diameter, the endotoxin level in HSA solution can be reduced to 0.027 eu/mL. Recovery of HSA was over 95%.
A novel matrix of macropore cellulose membrane was prepared by chemical graft, and immobilized the cationic charged groups as affinity ligands. The prepared membrane can be used for the removal of endotoxin from human serum albumin (HSA) solutions. With a cartridge of 20 sheets affinity membrane of 47 mm diameter, the endotoxin level in HSA solution can be reduced to 0.027 eu/mL. Recovery of HSA was over 95%.
2000, 11(4): 361-364
Abstract:
The crystallization behaviors of poly (3-dodecylthiophene) (P3DDT) under two different oriented solidification conditions, i.e., two different relative relations (90° and 180°) between the directions of gravity and solidification, were investigated. X-ray diffraction results reveal that although similar layered structures are formed, under the condition of the relative relation 180°, temperature gradient has greater effects on the perfect degree of the layered structures of P3DDT. It also can be concluded that after recrystallization, the layered structures of P3DDT can be improved at relative relation 90°, but the orderly degree of the arrangements of alkyl side chains are not improved yet, even is reduced for both of the oriented solidification conditions.
The crystallization behaviors of poly (3-dodecylthiophene) (P3DDT) under two different oriented solidification conditions, i.e., two different relative relations (90° and 180°) between the directions of gravity and solidification, were investigated. X-ray diffraction results reveal that although similar layered structures are formed, under the condition of the relative relation 180°, temperature gradient has greater effects on the perfect degree of the layered structures of P3DDT. It also can be concluded that after recrystallization, the layered structures of P3DDT can be improved at relative relation 90°, but the orderly degree of the arrangements of alkyl side chains are not improved yet, even is reduced for both of the oriented solidification conditions.
2000, 11(4): 365-366
Abstract:
α Form Nylon 11 films were found to exist a non-linear transformation at 70℃ during the heating process using in situ WAXD. The α Form disappeared but δ form appeared when the temperature was higher 70℃.
α Form Nylon 11 films were found to exist a non-linear transformation at 70℃ during the heating process using in situ WAXD. The α Form disappeared but δ form appeared when the temperature was higher 70℃.
2000, 11(4): 367-368
Abstract:
A series of syndiotactic polystyrene (SPS) samples in β crystalline form were prepared by cooling from the melt at various cooling rates. The effects of cooling rate from the melt, and DSC heating rate on the multiple melting behaviors of β crystals were investigated by differential scanning calorimetry (DSC) and modulated differential scanning calorimetry (MDSC), from which the nature.of the multiple melting behavior was ascribed to the occurring of a recrystallization process.
A series of syndiotactic polystyrene (SPS) samples in β crystalline form were prepared by cooling from the melt at various cooling rates. The effects of cooling rate from the melt, and DSC heating rate on the multiple melting behaviors of β crystals were investigated by differential scanning calorimetry (DSC) and modulated differential scanning calorimetry (MDSC), from which the nature.of the multiple melting behavior was ascribed to the occurring of a recrystallization process.
2000, 11(4): 369-372
Abstract:
Three Complexes of the formula[Cd (4,4'-bpy)2 (H2O)2]n (pic)2n (1),[Zn (4,4'-bpy)2 (H2O)2]n-(pic)2n (H2O)2n (2) and [Zn (4,4'-bpy)2 (H2O)2]n (4,4'-bpy)n (pic)2n (H2O)n (3) (4,4'-bpy=4,4'-bipyridine; pic=picric anion) have been synthesized and characterized by elemental analysis and single-crystal x-ray diffraction. They all have infinite three-dimensional network structure, crystallizing in the monoclinic space group C2/c (1) and Cc (2,3).
Three Complexes of the formula[Cd (4,4'-bpy)2 (H2O)2]n (pic)2n (1),[Zn (4,4'-bpy)2 (H2O)2]n-(pic)2n (H2O)2n (2) and [Zn (4,4'-bpy)2 (H2O)2]n (4,4'-bpy)n (pic)2n (H2O)n (3) (4,4'-bpy=4,4'-bipyridine; pic=picric anion) have been synthesized and characterized by elemental analysis and single-crystal x-ray diffraction. They all have infinite three-dimensional network structure, crystallizing in the monoclinic space group C2/c (1) and Cc (2,3).
2000, 11(4): 373-374
Abstract:
A novel ammonia synthesis catalyst, potassium-promoted ruthenium supported on carbon nanotubes, was developed. It was found that the Ru-K/carbon nanotubes catalyst had higher activity for ammonia synthesis (20.85 ml NH3/h/g-cat) than the Ru-K/fullerenes (13.3 ml NH3/h/g-cat) at atmospheric pressure and 623 K. The catalyst had activity even at 473 K. and had the highest activity (23.46 ml NH3/h/g-cat) at 643 K. It was suggested that the multi-walled structure favored the electron transfer the hydrogen-storage and the hydrogen-spill which were favorable to ammonia synthesis.
A novel ammonia synthesis catalyst, potassium-promoted ruthenium supported on carbon nanotubes, was developed. It was found that the Ru-K/carbon nanotubes catalyst had higher activity for ammonia synthesis (20.85 ml NH3/h/g-cat) than the Ru-K/fullerenes (13.3 ml NH3/h/g-cat) at atmospheric pressure and 623 K. The catalyst had activity even at 473 K. and had the highest activity (23.46 ml NH3/h/g-cat) at 643 K. It was suggested that the multi-walled structure favored the electron transfer the hydrogen-storage and the hydrogen-spill which were favorable to ammonia synthesis.
2000, 11(4): 375-376
Abstract:
A series of CdS nanoparticles with different surfaces were prepared by colloidal chemical method and reverse micelle method. Their second-order nonlinear optical (NLO) properties were experimentally studied in solution by newly developed hyper-Rayleigh scattering (HRS) technique. The results show that "per particle" first-order hyperpolarizability β values are sensitive to the synthetic method and the surface chemical modification.
A series of CdS nanoparticles with different surfaces were prepared by colloidal chemical method and reverse micelle method. Their second-order nonlinear optical (NLO) properties were experimentally studied in solution by newly developed hyper-Rayleigh scattering (HRS) technique. The results show that "per particle" first-order hyperpolarizability β values are sensitive to the synthetic method and the surface chemical modification.
