The 1-azido-2-chloro-4-nitrobenzene was prepared by nucleophilic substitution between 2-chloro-4-nitro-1-(trifluoromethylsulfinyl)benzene and sodium azide, and its structure was characterized by NMR spectrum and X-ray...The 1-azido-2-chloro-4-nitrobenzene was prepared by nucleophilic substitution between 2-chloro-4-nitro-1-(trifluoromethylsulfinyl)benzene and sodium azide, and its structure was characterized by NMR spectrum and X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group P21/n, Z = 8 and Mr = 198.57. A cultivation process of the single crystal of unstable aryl azide was provided. The group of trifluoromethyl sulfinyl was found for the first time to be a new excellent leaving group of aromatic nucleophilic substitution reactions.展开更多
The catalysis of ionic liquids (ILs) in the traditional stirred reactor suffers from insufficient mass and heat transfer, which always needs a long reaction time and results in a low reaction rate. In this work, highl...The catalysis of ionic liquids (ILs) in the traditional stirred reactor suffers from insufficient mass and heat transfer, which always needs a long reaction time and results in a low reaction rate. In this work, highly efficient synthesis of 1-methoxy-2-propanol via the alcoholysis reaction of propylene oxide (PO) with methanol was proposed and achieved by the combination of micro-tubular circulating reactor with the IL [N4444] [Buty] catalyst. Compared with the stirred reactor, the rate of alcoholysis reaction in a micro-tubular circulating reactor was found to be significantly improved. The reaction time was remarkably shortened to 20 min from 180 min as well as the yield of 1-methoxy-2-propanol reached 92%. Moreover, the kinetic study further demonstrated that the main reaction rate to 1-methoxy-2-propanol (K1) was about 20 times larger than the side reaction rate to byproduct 2-methoxy-1-propanol (K2) in the temperature range of 363–383 K. Such combination of micro-tubular circulating reactor with IL catalysts is believed to be a class of effective process intensification technique for highly efficient synthesis of 1-methoxy-2-propanol.展开更多
The title compound, (E)-1-(7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl)- 3-(2-methoxyphenyl)-2-(1H-1,2,4-triazol-1-yl)propenol (3a), was synthesized by the Aldol con- densation reaction of 1-(7-methox...The title compound, (E)-1-(7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl)- 3-(2-methoxyphenyl)-2-(1H-1,2,4-triazol-1-yl)propenol (3a), was synthesized by the Aldol con- densation reaction of 1-(7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl)-2-(1,2,4-triazol- 1-yl)ethanone with 2-methoxybenzaldehyde and then reduced with NaBH4, and its crystal structure was determined by single-crystal X-ray diffraction: monoclinic system, space group P21 with a = 6.2002(3), b = 12.8452(7), c = 13.2257(7) ?, Z = 2, V = 1031.23(9) ?3, Mr = 407.46, Dc = 1.312 Mg/m3, S = 1.054, μ = 0.091 mm-1, F(000) = 432, the final R = 0.0353 and wR = 0.0769 for 3161 observed reflections (I 〉 2σ(I)). X-ray analysis displays that the title compound adopts an E configuration for the C(7)=C(8) double bond and S configuration for the chirality center with the specific rotation of –63.75°. Furthermore, the stability of the crystal was maintained through the intermolecular hydrogen bond O(1)–H???N(3). The antitumor assay exhibits that the title compound 3a (E configuration) has a good antitumor activity against the Hela cell line with the IC50 value of 36.9 μM, which is better than that of 3b (Z configuration).展开更多
Cultivation of an endophytic fungus Aspergillus niger EN-13 that was isolated from the inner tissue of the marine brown alga Colpomenia sinuosa resulted in the characterization of a new naphthoquinoneimine derivative,...Cultivation of an endophytic fungus Aspergillus niger EN-13 that was isolated from the inner tissue of the marine brown alga Colpomenia sinuosa resulted in the characterization of a new naphthoquinoneimine derivative, namely, 5,7-dihydroxy-2-[1-(4- methoxy-6-oxo-6H-pyran-2-yl)-2-phenylethylamino]-[ 1,4]naphthoquinone. The structure of the new compound was established on the basis of various NMR spectroscopic analyses including 2D NMR techniques, El-MS, and HR-ESI-MS. This compound displayed moderate antifungal activity.展开更多
The kinetics of oxidation of 1-methoxy-2-propanol and l-ethoxy-2-propanol by ditelluratocuprate(III) (DTC) in alkaline liquids has been studied spectrophotometrically in the temperature range of 293.2-313.2 K. The...The kinetics of oxidation of 1-methoxy-2-propanol and l-ethoxy-2-propanol by ditelluratocuprate(III) (DTC) in alkaline liquids has been studied spectrophotometrically in the temperature range of 293.2-313.2 K. The reaction rate showed first order dependence in DTC and fractional order with respect to l-methoxy-2-propanol or 1-ethoxy-2-propanol. It was found that the pseudo-first order rate constant kobs increased with an increase in concentration of OH- and a decrease in concentration of TeO4^2- . There is a negative salt effect. A plausible mechanism involving a pre-equilibrium of a adduct formation between the complex and 1-methoxy-2-propanol or 1-ethoxy-2-propanol was proposed. The rate equations derived from mechanism can explain all experimental observations. The activation parameters along with the rate constants of the rate-determining step were calculated.展开更多
The title compound (1) was prepared via methylene blue (MB)-sensitized photooxygenation of 1-methyl-2-phenylindole (2d) in methanol. Acid-catalyzed nucleophilic substitution of 1 with nucleophiles gave 1,2,2-trisubsti...The title compound (1) was prepared via methylene blue (MB)-sensitized photooxygenation of 1-methyl-2-phenylindole (2d) in methanol. Acid-catalyzed nucleophilic substitution of 1 with nucleophiles gave 1,2,2-trisubstituted 3-oxo-2,3-dihydroindoles (3-6). lithium aluminum hydride, followed by acidic workup yielded 4d and 2d, whereas the same reduction reaction of 1, followed by neutral workup gave 1-methyl-2-phenyl-3-hydroxy-2,3-dihydroindole (15), together with 3. The reaction pathways of nucleophilic substitution and reduction of 1 were discussed.展开更多
The inhibitory effect of the methanolic extract of the root of Aegle marmelos (MERA) and its constituents on the lipid peroxidation in vivo and in vitro were studied. The results suggested that MERA increased the acti...The inhibitory effect of the methanolic extract of the root of Aegle marmelos (MERA) and its constituents on the lipid peroxidation in vivo and in vitro were studied. The results suggested that MERA increased the activities of superoxide dismutase (SOD) and GSH-peroxidase in the liver cytosol of mice, but showed no significant effect on the activity of catalase, and one of its major constituents, 4-methoxy-1-methyl-2-quinolone (MMQ) increased the activity of SOD in liver tissue of mice intoxicated with FeCl2-ascorbic acid (AA)-ADP in vivo. Various constituents isolated from the root of title plant inhibited the lipid peroxidation in rat liver homogenate, which was in vitro induced by FeCl2-ascorbic acid, CCl4-NADPH, or ADP- NADPH. Of the test compounds, MMQ and its derivatives integriquinolone were similar to (-tocopherol in inhibiting MDA production in rat liver microsomes induced by Fe2+-ascorbate, CCl4-NADPH, or ADP-NADPH.展开更多
The photo-controlled/living radical polymerization of methacrylic acid (MAA) was performed at room temperature by irradiation with a high-pressure mercury lamp using azo initiators and 4-methoxy-2,2,6,6-tetramethylpip...The photo-controlled/living radical polymerization of methacrylic acid (MAA) was performed at room temperature by irradiation with a high-pressure mercury lamp using azo initiators and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl as the mediator in the presence of (4-tert-butylphenyl)diphenylsulfonium triflate (tBuS) as the accelerator. Whereas the bulk polymerization yielded polymers with a bimodal molecular weight distribution in both the absence and presence of tBuS, the solution polymerization in methanol produced unimodal polymers with the molecular weight distribution of 2.0 - 2.3 in the presence of tBuS. The molecular weight distribution of the resulting poly (MAA) decreased with an in- crease in tBuS. The dilution of the monomer concentration also reduced the molecular weight distribution. The use of the initiator with a low 10-h half-life temperature also effectively controlled the molecular weight. The livingness of the polymerization was confirmed by obtaining linear increases in the first-order conversion versus time, the molecular weight versus the conversion, and the molecular weight versus the reciprocal of the initiator concentration.展开更多
Nano-NiO and bulk NiO were prepared from Ni(AC)_2·4 H_2O by coordination precipitation using aqueous ammonia and by a solid state reaction, respectively. The nickel oxide particles were characterized by X-ray Dif...Nano-NiO and bulk NiO were prepared from Ni(AC)_2·4 H_2O by coordination precipitation using aqueous ammonia and by a solid state reaction, respectively. The nickel oxide particles were characterized by X-ray Diffraction(XRD) and scanning electron microscopy(SEM). The results indicate that nano-sized NiO has a crystal phase with a standard face-centered cubic lattice structure, with a mean particle diameter of about 10 nm. The evaluation of the activity of nickel oxide nanoparticles in the catalytic hydrogenation of 7-methoxy-1-naphthylacetonitrile was carried out. The results demonstrate the efficient synthesis of the title compound by a one-pot catalytic hydrogenation and acetylation with NiO. The NiO nanoparticles displayed superior catalytic activity in the synthesis of agomelatine in the one-pot reaction.The total yield of agomelatine is over 81.8% with a purity of 99.2%, as determined by HPLC. The structure of agomelatine was confirmed by IR, MS, and 1 H NMR analysis.展开更多
The acceleration mechanisms by a photosensitive onium salt for the nitroxide-mediated photocontrolled/living radical polymerization (photo-NMP) were determined. The photo-NMP of methyl methacrylate was performed by ir...The acceleration mechanisms by a photosensitive onium salt for the nitroxide-mediated photocontrolled/living radical polymerization (photo-NMP) were determined. The photo-NMP of methyl methacrylate was performed by irradiation at room temperature using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (MTEMPO) as the mediator and (2RS, 2’RS)-azobis(4-methoxy-2,4-dimethylvaleronitrile) as the initiator. The polymerization was accelerated in the presence of (4-tertbutylphenyl)diphenylsulfonium triflate (tBuS) to produce a polymer with a molecular weight distribution as narrow as the polymerization in its absence. (±)-Camphor-10-sulfonic acid or 2-fluoro-1-methylpyridinium p-toluenesulfonate had no effect on the polymerization speed, suggesting that tBuS did not serve as the photo-acid generator for the photo-NMP. It was found that the acceleration of the polymerization was based on the electron transfer from MTEMPO into tBuS in the excited state to temporarily generate a free radical propagating chain end and an oxoaminium salt (OAS), the one-electron oxidant of MTEMPO. This electron transfer mechanism was verified on the basis of the fact that the photo-NMP in the presence of tBuS was still accelerated by triphenylamine, the electron transfer inhibitor, to partly produce a polymer with an uncontrolled molecular weight. The formation of an uncontrolled molecular weight polymer indicated the generation of a free radical propagating chain end due to the deactivation of the OAS by the triphenylamine. It was deduced that tBuS served as the electron acceptor from MTEMPO in the excited state to temporarily produce a free radical propagating chain end along with OAS, resulting in the acceleration of the polymerization.展开更多
Two new isoflavonoid glucosides, 5-hydroxy-6,7-methylenedioxy-isoflavone-4'-O-D-glucopyranosyl (2→〉l)-L-rhamnoside (irilone-bioside) (compound 1) and 5,4'-methoxy-6,7-methylenedioxyisoflavone-3'-O-β-D-gluc...Two new isoflavonoid glucosides, 5-hydroxy-6,7-methylenedioxy-isoflavone-4'-O-D-glucopyranosyl (2→〉l)-L-rhamnoside (irilone-bioside) (compound 1) and 5,4'-methoxy-6,7-methylenedioxyisoflavone-3'-O-β-D-glucoside (irisleptophyllidin) (compound 2), together with five known compounds, nigricanin- 4'-O-β-D-glucoside (compound 3), irifloside (compound 4), irigenin (compound 5), 5, 3', 4'-trimethoxy-6,7-methylenedioxyisoflavone (compound 6), and nigricanin (compound 7) were isolated from the alcoholic extract of rhizomes of Iris leptophylla Lingelsh. Their structures were elucidated by spectroscopic methods.展开更多
文摘The 1-azido-2-chloro-4-nitrobenzene was prepared by nucleophilic substitution between 2-chloro-4-nitro-1-(trifluoromethylsulfinyl)benzene and sodium azide, and its structure was characterized by NMR spectrum and X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group P21/n, Z = 8 and Mr = 198.57. A cultivation process of the single crystal of unstable aryl azide was provided. The group of trifluoromethyl sulfinyl was found for the first time to be a new excellent leaving group of aromatic nucleophilic substitution reactions.
基金We thank the National Natural Science Foundations of China(Nos.21566011,31570560)the Jiangxi Province Sponsored Programs for Distinguished Young Scholars(No.20162BCB23026)and the Science&Technology Programs of Jiangxi Province Department of Education(No.GJJ160272)for financial support.
文摘The catalysis of ionic liquids (ILs) in the traditional stirred reactor suffers from insufficient mass and heat transfer, which always needs a long reaction time and results in a low reaction rate. In this work, highly efficient synthesis of 1-methoxy-2-propanol via the alcoholysis reaction of propylene oxide (PO) with methanol was proposed and achieved by the combination of micro-tubular circulating reactor with the IL [N4444] [Buty] catalyst. Compared with the stirred reactor, the rate of alcoholysis reaction in a micro-tubular circulating reactor was found to be significantly improved. The reaction time was remarkably shortened to 20 min from 180 min as well as the yield of 1-methoxy-2-propanol reached 92%. Moreover, the kinetic study further demonstrated that the main reaction rate to 1-methoxy-2-propanol (K1) was about 20 times larger than the side reaction rate to byproduct 2-methoxy-1-propanol (K2) in the temperature range of 363–383 K. Such combination of micro-tubular circulating reactor with IL catalysts is believed to be a class of effective process intensification technique for highly efficient synthesis of 1-methoxy-2-propanol.
基金Project supported by the National Natural Science Foundation of China(No.21442014)
文摘The title compound, (E)-1-(7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl)- 3-(2-methoxyphenyl)-2-(1H-1,2,4-triazol-1-yl)propenol (3a), was synthesized by the Aldol con- densation reaction of 1-(7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl)-2-(1,2,4-triazol- 1-yl)ethanone with 2-methoxybenzaldehyde and then reduced with NaBH4, and its crystal structure was determined by single-crystal X-ray diffraction: monoclinic system, space group P21 with a = 6.2002(3), b = 12.8452(7), c = 13.2257(7) ?, Z = 2, V = 1031.23(9) ?3, Mr = 407.46, Dc = 1.312 Mg/m3, S = 1.054, μ = 0.091 mm-1, F(000) = 432, the final R = 0.0353 and wR = 0.0769 for 3161 observed reflections (I 〉 2σ(I)). X-ray analysis displays that the title compound adopts an E configuration for the C(7)=C(8) double bond and S configuration for the chirality center with the specific rotation of –63.75°. Furthermore, the stability of the crystal was maintained through the intermolecular hydrogen bond O(1)–H???N(3). The antitumor assay exhibits that the title compound 3a (E configuration) has a good antitumor activity against the Hela cell line with the IC50 value of 36.9 μM, which is better than that of 3b (Z configuration).
基金partially supported by the fund of Key Laboratory of Marine Drugs(0cean University of China),Ministry of Education[KLMD(0UC)2004]by the National Natural Science Foundation of China(No.30530080)+1 种基金A program supported by the Department of Science and Technology of Shandong Province(No.2006GG2205023)by the Guangdong Key Laboratory of Marine Materia Medica is also gratefully acknowledged.
文摘Cultivation of an endophytic fungus Aspergillus niger EN-13 that was isolated from the inner tissue of the marine brown alga Colpomenia sinuosa resulted in the characterization of a new naphthoquinoneimine derivative, namely, 5,7-dihydroxy-2-[1-(4- methoxy-6-oxo-6H-pyran-2-yl)-2-phenylethylamino]-[ 1,4]naphthoquinone. The structure of the new compound was established on the basis of various NMR spectroscopic analyses including 2D NMR techniques, El-MS, and HR-ESI-MS. This compound displayed moderate antifungal activity.
文摘The kinetics of oxidation of 1-methoxy-2-propanol and l-ethoxy-2-propanol by ditelluratocuprate(III) (DTC) in alkaline liquids has been studied spectrophotometrically in the temperature range of 293.2-313.2 K. The reaction rate showed first order dependence in DTC and fractional order with respect to l-methoxy-2-propanol or 1-ethoxy-2-propanol. It was found that the pseudo-first order rate constant kobs increased with an increase in concentration of OH- and a decrease in concentration of TeO4^2- . There is a negative salt effect. A plausible mechanism involving a pre-equilibrium of a adduct formation between the complex and 1-methoxy-2-propanol or 1-ethoxy-2-propanol was proposed. The rate equations derived from mechanism can explain all experimental observations. The activation parameters along with the rate constants of the rate-determining step were calculated.
基金Project supported by the Coal Industry Universities Science Foundation of China.
文摘The title compound (1) was prepared via methylene blue (MB)-sensitized photooxygenation of 1-methyl-2-phenylindole (2d) in methanol. Acid-catalyzed nucleophilic substitution of 1 with nucleophiles gave 1,2,2-trisubstituted 3-oxo-2,3-dihydroindoles (3-6). lithium aluminum hydride, followed by acidic workup yielded 4d and 2d, whereas the same reduction reaction of 1, followed by neutral workup gave 1-methyl-2-phenyl-3-hydroxy-2,3-dihydroindole (15), together with 3. The reaction pathways of nucleophilic substitution and reduction of 1 were discussed.
文摘The inhibitory effect of the methanolic extract of the root of Aegle marmelos (MERA) and its constituents on the lipid peroxidation in vivo and in vitro were studied. The results suggested that MERA increased the activities of superoxide dismutase (SOD) and GSH-peroxidase in the liver cytosol of mice, but showed no significant effect on the activity of catalase, and one of its major constituents, 4-methoxy-1-methyl-2-quinolone (MMQ) increased the activity of SOD in liver tissue of mice intoxicated with FeCl2-ascorbic acid (AA)-ADP in vivo. Various constituents isolated from the root of title plant inhibited the lipid peroxidation in rat liver homogenate, which was in vitro induced by FeCl2-ascorbic acid, CCl4-NADPH, or ADP- NADPH. Of the test compounds, MMQ and its derivatives integriquinolone were similar to (-tocopherol in inhibiting MDA production in rat liver microsomes induced by Fe2+-ascorbate, CCl4-NADPH, or ADP-NADPH.
文摘The photo-controlled/living radical polymerization of methacrylic acid (MAA) was performed at room temperature by irradiation with a high-pressure mercury lamp using azo initiators and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl as the mediator in the presence of (4-tert-butylphenyl)diphenylsulfonium triflate (tBuS) as the accelerator. Whereas the bulk polymerization yielded polymers with a bimodal molecular weight distribution in both the absence and presence of tBuS, the solution polymerization in methanol produced unimodal polymers with the molecular weight distribution of 2.0 - 2.3 in the presence of tBuS. The molecular weight distribution of the resulting poly (MAA) decreased with an in- crease in tBuS. The dilution of the monomer concentration also reduced the molecular weight distribution. The use of the initiator with a low 10-h half-life temperature also effectively controlled the molecular weight. The livingness of the polymerization was confirmed by obtaining linear increases in the first-order conversion versus time, the molecular weight versus the conversion, and the molecular weight versus the reciprocal of the initiator concentration.
基金Funded by the Natural Science Foundation of Hubei Province(2017CFB680)the Hubei University of Science and Technology Nuclear Technology Special Project(2018-19KZ06)+1 种基金the Open Fund of the State Key Laboratory of Refractories and Metallurgy(Wuhan University of Science and Technology)of China(G201703)the Key Laboratory of Measurement and Control System for Offshore Environment,Fuqing Branch of Fujian Normal University,Fujian Province University(S1-KF1604)
文摘Nano-NiO and bulk NiO were prepared from Ni(AC)_2·4 H_2O by coordination precipitation using aqueous ammonia and by a solid state reaction, respectively. The nickel oxide particles were characterized by X-ray Diffraction(XRD) and scanning electron microscopy(SEM). The results indicate that nano-sized NiO has a crystal phase with a standard face-centered cubic lattice structure, with a mean particle diameter of about 10 nm. The evaluation of the activity of nickel oxide nanoparticles in the catalytic hydrogenation of 7-methoxy-1-naphthylacetonitrile was carried out. The results demonstrate the efficient synthesis of the title compound by a one-pot catalytic hydrogenation and acetylation with NiO. The NiO nanoparticles displayed superior catalytic activity in the synthesis of agomelatine in the one-pot reaction.The total yield of agomelatine is over 81.8% with a purity of 99.2%, as determined by HPLC. The structure of agomelatine was confirmed by IR, MS, and 1 H NMR analysis.
文摘The acceleration mechanisms by a photosensitive onium salt for the nitroxide-mediated photocontrolled/living radical polymerization (photo-NMP) were determined. The photo-NMP of methyl methacrylate was performed by irradiation at room temperature using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (MTEMPO) as the mediator and (2RS, 2’RS)-azobis(4-methoxy-2,4-dimethylvaleronitrile) as the initiator. The polymerization was accelerated in the presence of (4-tertbutylphenyl)diphenylsulfonium triflate (tBuS) to produce a polymer with a molecular weight distribution as narrow as the polymerization in its absence. (±)-Camphor-10-sulfonic acid or 2-fluoro-1-methylpyridinium p-toluenesulfonate had no effect on the polymerization speed, suggesting that tBuS did not serve as the photo-acid generator for the photo-NMP. It was found that the acceleration of the polymerization was based on the electron transfer from MTEMPO into tBuS in the excited state to temporarily generate a free radical propagating chain end and an oxoaminium salt (OAS), the one-electron oxidant of MTEMPO. This electron transfer mechanism was verified on the basis of the fact that the photo-NMP in the presence of tBuS was still accelerated by triphenylamine, the electron transfer inhibitor, to partly produce a polymer with an uncontrolled molecular weight. The formation of an uncontrolled molecular weight polymer indicated the generation of a free radical propagating chain end due to the deactivation of the OAS by the triphenylamine. It was deduced that tBuS served as the electron acceptor from MTEMPO in the excited state to temporarily produce a free radical propagating chain end along with OAS, resulting in the acceleration of the polymerization.
基金Supported by the National Natural Science Foundation of China (30170103).
文摘Two new isoflavonoid glucosides, 5-hydroxy-6,7-methylenedioxy-isoflavone-4'-O-D-glucopyranosyl (2→〉l)-L-rhamnoside (irilone-bioside) (compound 1) and 5,4'-methoxy-6,7-methylenedioxyisoflavone-3'-O-β-D-glucoside (irisleptophyllidin) (compound 2), together with five known compounds, nigricanin- 4'-O-β-D-glucoside (compound 3), irifloside (compound 4), irigenin (compound 5), 5, 3', 4'-trimethoxy-6,7-methylenedioxyisoflavone (compound 6), and nigricanin (compound 7) were isolated from the alcoholic extract of rhizomes of Iris leptophylla Lingelsh. Their structures were elucidated by spectroscopic methods.