a-Bromo benzoylmethylene triphenylphosphorane 3 has been synthesized by the reaction of benzoylmethylene triphenylphosphorane 1 with N-bromosuccinimide in the yield of 87% and can react with aromatic aldehydes 4 to gi...a-Bromo benzoylmethylene triphenylphosphorane 3 has been synthesized by the reaction of benzoylmethylene triphenylphosphorane 1 with N-bromosuccinimide in the yield of 87% and can react with aromatic aldehydes 4 to give-bromochalcones 5 in good yields.展开更多
A new approach to the synthesis of co -bromo-dienes was carried out by usingsolid/liquid transferred Wittig reactions between in -bromobutyltriphenylphosphoniumsalt and Q. 6 -unsaturated aldehydes.
The reaction mechanism of 2-methoxybenzaldehyde, 4-bromo-indanone, malononitrile and ammonium acetate one-pot to form 6-(2-methoxyphenyl)-2-amino-6-bromo-5 Hindeno[1,2-b]pyridine-3-carbonitrile was studied by densit...The reaction mechanism of 2-methoxybenzaldehyde, 4-bromo-indanone, malononitrile and ammonium acetate one-pot to form 6-(2-methoxyphenyl)-2-amino-6-bromo-5 Hindeno[1,2-b]pyridine-3-carbonitrile was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Reaction pathways were investigated in this study. The result indicates that the reaction Re→ TSB1→IMB1→ TSB2→ IMB2→TSB3→IMB3→TSB4→IMB4→TSB5→IMB5→TSB6→IMB6→TSB7→IMB7→ TSB8→IMB8→TSB9→IMB9→P2 is the main pathway, the activation energy of which is the lowest. The dominant product predicted theoretically is in agreement with the experiment results.展开更多
AIM:To investigate whether the apoptotic activities of 8-bromo-7-methoxychrysin(BrMC) involve reactive oxygen species(ROS) generation and c-Jun N-terminal kinase(JNK) activation in human hepatocellular carcinoma cells...AIM:To investigate whether the apoptotic activities of 8-bromo-7-methoxychrysin(BrMC) involve reactive oxygen species(ROS) generation and c-Jun N-terminal kinase(JNK) activation in human hepatocellular carcinoma cells(HCC).METHODS:HepG2,Bel-7402 and L-02 cell lines were cultured in vitro and the apoptotic effects of BrMC were evaluated by flow cytometry(FCM) after propidium iodide(PI) staining,caspase-3 activity using enzymelinked immunosorbent assay(ELISA),and DNA agarose gel electrophoresis.ROS production was evaluated by FCM after dichlorodihydrofluorescein diacetate(DCHFDA) probe labeling.The phosphorylation level of JNK and c-Jun protein was analyzed by Western blotting.RESULTS:FCM after PI staining showed a dose-dependent increase in the percentage of the sub-G1 cell pop-ulation(P < 0.05),reaching 39.0% ± 2.8% of HepG2 cells after 48 h of treatment with BrMC at 10 μmol/L.The potency of BrMC to HepG2 and Bel-7402(32.1% ± 2.6%) cells was found to be more effective than the lead compound,chrysin(16.2% ± 1.6% for HepG2 cells and 11.0% ± 1.3% for Bel-7402 cell) at 40 μmol/L and similar to 5-flurouracil(33.0% ± 2.1% for HepG2 cells and 29.3% ± 2.3% for Bel-7402 cells) at 10 μmol/L.BrMC had little effect on human embryo liver L-02 cells,with the percentage of sub-G1 cell population 5.4% ± 1.8%.Treatment of HepG2 cells with BrMC for 48 h also increased the levels of active caspase-3,in a concentration-dependent manner.z-DEVD-fmk,a caspase-3specific inhibitor,prevented the activation of caspase-3.Treatment with BrMC at 10 μmol/L for 48 h resulted in the formation of a DNA ladder.Treatment of cells with BrMC(10 μmol/L) increased mean fluorescence intensity of DCHF-DA in HepG2 cells from 7.2 ± 1.12 at 0 h to 79.8 ± 3.9 at 3 h and 89.7 ± 4.7 at 6 h.BrMC did not affect ROS generation in L-02 cells.BrMC treatment failed to induce cell death and caspase-3 activation in HepG2 cells pretreated with N-acetylcysteine(10 mmol/L).In addition,in HepG2 cells treated with BrMC(2.5,5.0,10.0 μmol/L) for 12 h,JNK activation was observed.Peak JNK activation occurred at 12 h post-treatment and this activation persisted for up to 24 h.The expression of phosphorylated JNK and c-Jun protein after 12 h with BrMC-treated cells was inhibited by N-acetylcysteine and SP600125 pre-treatment,but GW9662 had no effect.SP600125 substantially reduced BrMC-induced cell death and caspase-3 activation of HepG2 cells.N-acetylcysteine and GW9662 also attenuated induction of cell death and caspase-3 activation in HepG2 cells treated with BrMC.CONCLUSION:BrMC induces apoptosis of HCC cells by ROS generation and sustained JNK activation.展开更多
Objective 1-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) is a solid oxidizing biocide for water disinfection.The objective of this study was to investigate the toxic effect of BCDMH on zebrafish.Methods The developm...Objective 1-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) is a solid oxidizing biocide for water disinfection.The objective of this study was to investigate the toxic effect of BCDMH on zebrafish.Methods The developmental toxicity of BCDMH on zebrafish embryos and the dose-effect relationship was determined.The effect of BCDMH exposure on histopathology and tissue antioxidant activity of adult zebrafish were observed over time.Results Exposure to 4 mg/L BCDMH post-fertilization was sufficient to induce a number of developmental malformations,such as edema,axial malformations,and reductions in heart rate and hatching rate.The no observable effects concentration of BCDMH on zebrafish embryo was 0.5 mg/L.After 96 h exposure,the 50% lethal concentration (95% confidence interval (CI)) of BCDMH on zebrafish embryo was 8.10 mg/L (6.15-11.16 mg/L).The 50% inhibitory concentration (95% CI) of BCDMH on hatching rate was 7.37 mg/L (6.33-8.35 mg/L).Histopathology showed two types of responses induced by BCDMH,defensive and compensatory.The extreme responses were marked hyperplasia of the gill epithelium with lamellar fusion and epidermal peeling.The histopathologic changes in the gills after 10 days exposure were accompanied by significantly higher catalase activity and lipid peroxidation.Conclusion These results have important implications for studies on the toxicity and use of BCDMH and its analogs.展开更多
Methyl 12-bromo-13,14-furoxan-deisopropyldehydroabietate, C18H22BrN2O4, has been synthesized and characterized by IR,^1H NMR, ^13C NMR and single-crystal X-ray diffraction method. It crystallizes in orthorhombic, spac...Methyl 12-bromo-13,14-furoxan-deisopropyldehydroabietate, C18H22BrN2O4, has been synthesized and characterized by IR,^1H NMR, ^13C NMR and single-crystal X-ray diffraction method. It crystallizes in orthorhombic, space group P212121 with a = 6.652(2), b = 12.832(4), c = 20.483(6)°A, V = 1748.5(9) °A^3, Z = 4, Mr = 410.29, D, = 1.559 g/cm^3, λ= 0.71070°A, μ(MoKα) = 2.377 mm^-1, F(000) = 844, the final R = 0.0243 and wR = 0.0533 for 3780 observed reflections with I〉 2σ(I). The C-H and bromine atom are involved in intermolecular hydrogen bonds which link the molecules into a one-dimensional chain.展开更多
The title compound (C10H11BrO4, Mr = 275.10) was synthesized and its crystal structure has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 7.2960(8), b = 1...The title compound (C10H11BrO4, Mr = 275.10) was synthesized and its crystal structure has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 7.2960(8), b = 12.209(1), c = 12.568(1) ? b = 98.120(2)? l = 0.71073 ? m(MoKa) = 3.700 mm-1, V = 1108.3(2) 3, Z = 4, Dc = 1.649 g/cm3 and F(000) = 552. The structure was solved by direct methods and refined by full-matrix least-squares methods. R = 0.0375 and wR = 0.0864 for 1598 reflections with I > 2s(I). X-ray diffraction reveals that there exist two rings in the molecule, and the dihedral between them is 177.5?展开更多
We have presented the synthesis and characterization of three new bromo substituted stilbene derivatives, p-3,4,5-trimethoxy-p′- 2,3,4,5,6-pentabromostilbene (C1), p-N,N-dimethylamino-p′-2,3,4,5,6-pentabromostilbe...We have presented the synthesis and characterization of three new bromo substituted stilbene derivatives, p-3,4,5-trimethoxy-p′- 2,3,4,5,6-pentabromostilbene (C1), p-N,N-dimethylamino-p′-2,3,4,5,6-pentabromostilbene (C2) and p-N,N-diphenylamino-p′- 2,3,4,5,6-pentabromostilbene (C3) in this letter. The UV/vis absorption and photoluminescence were investigated in various solvents. The maximal absorption wavelength of C1 exhibited blue-shift to those of C2 and C3 in different solvents. No florescence emission could be detected for these compounds at room temperature. Singlet oxygen could be efficiently produced with these sensitizers under near-ultraviolet and visible light irradiation.展开更多
Several 14 alpha- and 14 beta -bromo baccatin III derivatives were synthesized by direct bromination and from silyl enol ether of 13-oxo-7-TES-baccatin III. 14 beta -Hyroxy baccatin III derivative was also obtained fr...Several 14 alpha- and 14 beta -bromo baccatin III derivatives were synthesized by direct bromination and from silyl enol ether of 13-oxo-7-TES-baccatin III. 14 beta -Hyroxy baccatin III derivative was also obtained from the same silyl enol ether.展开更多
Some new derivatives of 3-ethoxycarbonyl-6-bromo-5-hydroxyindoles were designed and prepared, their antiviral activity were determined in cell culture with virus cytopathic effect assay. The results showed compound ...Some new derivatives of 3-ethoxycarbonyl-6-bromo-5-hydroxyindoles were designed and prepared, their antiviral activity were determined in cell culture with virus cytopathic effect assay. The results showed compound Ⅶ b, Ⅶ h exhibited potential antiviral activity.展开更多
オhe fluorescent reagent, salicylaldehyde-5-bromo-salicyloylhydrazone (SABSH) was synthesized and its ionization constants were determined spectrophotometrically. The fluorescent reaction of this reagent with gallium ...オhe fluorescent reagent, salicylaldehyde-5-bromo-salicyloylhydrazone (SABSH) was synthesized and its ionization constants were determined spectrophotometrically. The fluorescent reaction of this reagent with gallium was studied. Based on this chelation reaction, a highly sensitive spectrofluorometric method was developed for the determination of gallium in a ethanol-water (3+2, V/V) medium at pH 2.3. Under these conditions, the GaⅢSABSH complex has excitation and emission maxima at 390 and 457 nm, respectively. The linear range of the method is from 0.0 to 1×10-4 g/L and the detection limit is 4×10-7 g/L of gallium when a standard additions method is used. The molar ratio of gallium to the reagent is 1∶1. Interferences were evaluated. The method was successfully applied to the determination of gallium in soil samples. Extraction with n-butyl acetate from 6 mol/L hydrochloric acid medium was used to separate gallium from the interfering elements in the soil samples.展开更多
The new synthesis of 10-bromo-α-chamigrene was achieved as follows; 6-methyl-5-heptene-2-one was transformed into corresponding thioacetals, and then successively treated with Cp2Ti(P(OEt)3)2. The intermediate re...The new synthesis of 10-bromo-α-chamigrene was achieved as follows; 6-methyl-5-heptene-2-one was transformed into corresponding thioacetals, and then successively treated with Cp2Ti(P(OEt)3)2. The intermediate reacted with mono-ketal of cyclohexane-1,4-dione, and gave the carbonyl coupling product. It was then transformed into the key intermediate γ-bisabolene via deketalization, Grignard reaction, dehydration and then furnished the target molecule by polyene cyclization, with total yield 2%. All structures were confirmed by ^1H NMR and ^13C NMR. The final compound was confirmed by ^1H NMR, ^13C NMR and MS.展开更多
Photopromoted carbonylation of 1-bromo-6-chlorohexane with CO catalyzed by CuBr2 and CdI2 has been carried out under ambient conditions. The results indicate that the carbonylation proceeds with the major product of c...Photopromoted carbonylation of 1-bromo-6-chlorohexane with CO catalyzed by CuBr2 and CdI2 has been carried out under ambient conditions. The results indicate that the carbonylation proceeds with the major product of chloroester ClCH2(CH2)5COOCH3 under catalysis of CuBr2. Furthermore, the activity of the carbonylation can be improved by addition of basic additives (NaOAc, Na3PO4 or (n-C4H9)3N). Among these additives, (n-C4H9)3N is the most efficient in terms of the yield of ClCH2(CH2)5COOCH3. However, the methoxycarbonyl substituting chlorine product of BrCH2(CH2)5COOCH3 is not obtained in the presence of CdI2. This is quite different from the carbonylation of monochloroalkane.展开更多
The reaction of aromatic carboxylic acid with oxalyl chloride gives rise to the corres- ponding acid chloride which without purification is treated with the sodium salt of mercapto- pyridine oxide in the presence of...The reaction of aromatic carboxylic acid with oxalyl chloride gives rise to the corres- ponding acid chloride which without purification is treated with the sodium salt of mercapto- pyridine oxide in the presence of 2,2-azo-bisisobutyronitrile (AIBN), radical initiator to give a brominated aromatic compound. After etherification and oxidation, 5-iodovaniline was converted to trisubstituted benzene carboxylic acid which give 1-bromo-3-methoxy-4-propoxy-5-iodo- benzene by this new brominating process with a yield of 74 %.展开更多
The title complex [Zn(L)(phen)(CH3OH)] (L = C8H6BrO4NS, aminomethanesulfonic acid 5-bromo-salicylaldelyde schiff base; phen = 1,10-phenanthroline) has been synthesized and characterized by X-ray diffraction me...The title complex [Zn(L)(phen)(CH3OH)] (L = C8H6BrO4NS, aminomethanesulfonic acid 5-bromo-salicylaldelyde schiff base; phen = 1,10-phenanthroline) has been synthesized and characterized by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/c with a = 1.8712(3), b = 1.38008(19), c = 0.83685(12) nm, β = 97.791 (2)°, Mr = 569.72, V = 2.1411 (5) nm^3, Z= 4, Dc = 1.767 g/cm^3,μ = 3.151 mm^-1, F(000) = 1144, the final R = 0.0402 and wR = 0.0885. The central Zn(Ⅱ) is six-coordinated by one nitrogen and two oxygen atoms from the Schiff base, two nitrogen atoms from 1,10-phenanthroline and one oxygen from methanol to form a distorted octahedral coordination geometry.展开更多
Sodium deoxycholate (NaDOC) could induce 1-bromo-4-(bromoacetyl) naphthalene (BBAN) to emit strong room temperature phosphorescence (RTP). Measurements of phosphore- scence spectra, peak intensity and polarization we...Sodium deoxycholate (NaDOC) could induce 1-bromo-4-(bromoacetyl) naphthalene (BBAN) to emit strong room temperature phosphorescence (RTP). Measurements of phosphore- scence spectra, peak intensity and polarization were used to investigate the solubilization of BBAN as a function of NaDOC concentration.展开更多
A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.
基金We thank the National Natural Science Foundation of China for financial support of the project 29972036.
文摘a-Bromo benzoylmethylene triphenylphosphorane 3 has been synthesized by the reaction of benzoylmethylene triphenylphosphorane 1 with N-bromosuccinimide in the yield of 87% and can react with aromatic aldehydes 4 to give-bromochalcones 5 in good yields.
文摘A new approach to the synthesis of co -bromo-dienes was carried out by usingsolid/liquid transferred Wittig reactions between in -bromobutyltriphenylphosphoniumsalt and Q. 6 -unsaturated aldehydes.
基金Project supported by the Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ1601215,KJ15012002)the Ministry of Education “Chunhui Plan”(Z2016177)
文摘The reaction mechanism of 2-methoxybenzaldehyde, 4-bromo-indanone, malononitrile and ammonium acetate one-pot to form 6-(2-methoxyphenyl)-2-amino-6-bromo-5 Hindeno[1,2-b]pyridine-3-carbonitrile was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Reaction pathways were investigated in this study. The result indicates that the reaction Re→ TSB1→IMB1→ TSB2→ IMB2→TSB3→IMB3→TSB4→IMB4→TSB5→IMB5→TSB6→IMB6→TSB7→IMB7→ TSB8→IMB8→TSB9→IMB9→P2 is the main pathway, the activation energy of which is the lowest. The dominant product predicted theoretically is in agreement with the experiment results.
基金Supported by Hunan Provincial Natural Science Foundation of China,No.03JJY5009
文摘AIM:To investigate whether the apoptotic activities of 8-bromo-7-methoxychrysin(BrMC) involve reactive oxygen species(ROS) generation and c-Jun N-terminal kinase(JNK) activation in human hepatocellular carcinoma cells(HCC).METHODS:HepG2,Bel-7402 and L-02 cell lines were cultured in vitro and the apoptotic effects of BrMC were evaluated by flow cytometry(FCM) after propidium iodide(PI) staining,caspase-3 activity using enzymelinked immunosorbent assay(ELISA),and DNA agarose gel electrophoresis.ROS production was evaluated by FCM after dichlorodihydrofluorescein diacetate(DCHFDA) probe labeling.The phosphorylation level of JNK and c-Jun protein was analyzed by Western blotting.RESULTS:FCM after PI staining showed a dose-dependent increase in the percentage of the sub-G1 cell pop-ulation(P < 0.05),reaching 39.0% ± 2.8% of HepG2 cells after 48 h of treatment with BrMC at 10 μmol/L.The potency of BrMC to HepG2 and Bel-7402(32.1% ± 2.6%) cells was found to be more effective than the lead compound,chrysin(16.2% ± 1.6% for HepG2 cells and 11.0% ± 1.3% for Bel-7402 cell) at 40 μmol/L and similar to 5-flurouracil(33.0% ± 2.1% for HepG2 cells and 29.3% ± 2.3% for Bel-7402 cells) at 10 μmol/L.BrMC had little effect on human embryo liver L-02 cells,with the percentage of sub-G1 cell population 5.4% ± 1.8%.Treatment of HepG2 cells with BrMC for 48 h also increased the levels of active caspase-3,in a concentration-dependent manner.z-DEVD-fmk,a caspase-3specific inhibitor,prevented the activation of caspase-3.Treatment with BrMC at 10 μmol/L for 48 h resulted in the formation of a DNA ladder.Treatment of cells with BrMC(10 μmol/L) increased mean fluorescence intensity of DCHF-DA in HepG2 cells from 7.2 ± 1.12 at 0 h to 79.8 ± 3.9 at 3 h and 89.7 ± 4.7 at 6 h.BrMC did not affect ROS generation in L-02 cells.BrMC treatment failed to induce cell death and caspase-3 activation in HepG2 cells pretreated with N-acetylcysteine(10 mmol/L).In addition,in HepG2 cells treated with BrMC(2.5,5.0,10.0 μmol/L) for 12 h,JNK activation was observed.Peak JNK activation occurred at 12 h post-treatment and this activation persisted for up to 24 h.The expression of phosphorylated JNK and c-Jun protein after 12 h with BrMC-treated cells was inhibited by N-acetylcysteine and SP600125 pre-treatment,but GW9662 had no effect.SP600125 substantially reduced BrMC-induced cell death and caspase-3 activation of HepG2 cells.N-acetylcysteine and GW9662 also attenuated induction of cell death and caspase-3 activation in HepG2 cells treated with BrMC.CONCLUSION:BrMC induces apoptosis of HCC cells by ROS generation and sustained JNK activation.
基金supported by the National Science and Technology Major Project "Creation of Major New Drugs", 2008ZX09305-001
文摘Objective 1-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) is a solid oxidizing biocide for water disinfection.The objective of this study was to investigate the toxic effect of BCDMH on zebrafish.Methods The developmental toxicity of BCDMH on zebrafish embryos and the dose-effect relationship was determined.The effect of BCDMH exposure on histopathology and tissue antioxidant activity of adult zebrafish were observed over time.Results Exposure to 4 mg/L BCDMH post-fertilization was sufficient to induce a number of developmental malformations,such as edema,axial malformations,and reductions in heart rate and hatching rate.The no observable effects concentration of BCDMH on zebrafish embryo was 0.5 mg/L.After 96 h exposure,the 50% lethal concentration (95% confidence interval (CI)) of BCDMH on zebrafish embryo was 8.10 mg/L (6.15-11.16 mg/L).The 50% inhibitory concentration (95% CI) of BCDMH on hatching rate was 7.37 mg/L (6.33-8.35 mg/L).Histopathology showed two types of responses induced by BCDMH,defensive and compensatory.The extreme responses were marked hyperplasia of the gill epithelium with lamellar fusion and epidermal peeling.The histopathologic changes in the gills after 10 days exposure were accompanied by significantly higher catalase activity and lipid peroxidation.Conclusion These results have important implications for studies on the toxicity and use of BCDMH and its analogs.
基金This work was financially supported by the National Natural Science Foundation of China (No. 20362002), the 100 Young and Middle-aged Disciplinary Leaders in Guangxi Higher Education Institutions and the Science Foundation for Youth of Guangxi Province (No. 0575046)
文摘Methyl 12-bromo-13,14-furoxan-deisopropyldehydroabietate, C18H22BrN2O4, has been synthesized and characterized by IR,^1H NMR, ^13C NMR and single-crystal X-ray diffraction method. It crystallizes in orthorhombic, space group P212121 with a = 6.652(2), b = 12.832(4), c = 20.483(6)°A, V = 1748.5(9) °A^3, Z = 4, Mr = 410.29, D, = 1.559 g/cm^3, λ= 0.71070°A, μ(MoKα) = 2.377 mm^-1, F(000) = 844, the final R = 0.0243 and wR = 0.0533 for 3780 observed reflections with I〉 2σ(I). The C-H and bromine atom are involved in intermolecular hydrogen bonds which link the molecules into a one-dimensional chain.
文摘The title compound (C10H11BrO4, Mr = 275.10) was synthesized and its crystal structure has been determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n with a = 7.2960(8), b = 12.209(1), c = 12.568(1) ? b = 98.120(2)? l = 0.71073 ? m(MoKa) = 3.700 mm-1, V = 1108.3(2) 3, Z = 4, Dc = 1.649 g/cm3 and F(000) = 552. The structure was solved by direct methods and refined by full-matrix least-squares methods. R = 0.0375 and wR = 0.0864 for 1598 reflections with I > 2s(I). X-ray diffraction reveals that there exist two rings in the molecule, and the dihedral between them is 177.5?
基金support from National Natural Science Foundation of China(Nos. 20776165,20702065,20872184)Key Foundation of Chongqing Science and Technology Commission"(No.CSTC 2008BA4020)+1 种基金"A Foundation for the Author of National Excellent Doctoral Dissertation of PR China(200735)"for financial supportsponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry as well(Nos.20071108-1, 20071108-5).
文摘We have presented the synthesis and characterization of three new bromo substituted stilbene derivatives, p-3,4,5-trimethoxy-p′- 2,3,4,5,6-pentabromostilbene (C1), p-N,N-dimethylamino-p′-2,3,4,5,6-pentabromostilbene (C2) and p-N,N-diphenylamino-p′- 2,3,4,5,6-pentabromostilbene (C3) in this letter. The UV/vis absorption and photoluminescence were investigated in various solvents. The maximal absorption wavelength of C1 exhibited blue-shift to those of C2 and C3 in different solvents. No florescence emission could be detected for these compounds at room temperature. Singlet oxygen could be efficiently produced with these sensitizers under near-ultraviolet and visible light irradiation.
文摘Several 14 alpha- and 14 beta -bromo baccatin III derivatives were synthesized by direct bromination and from silyl enol ether of 13-oxo-7-TES-baccatin III. 14 beta -Hyroxy baccatin III derivative was also obtained from the same silyl enol ether.
文摘Some new derivatives of 3-ethoxycarbonyl-6-bromo-5-hydroxyindoles were designed and prepared, their antiviral activity were determined in cell culture with virus cytopathic effect assay. The results showed compound Ⅶ b, Ⅶ h exhibited potential antiviral activity.
文摘オhe fluorescent reagent, salicylaldehyde-5-bromo-salicyloylhydrazone (SABSH) was synthesized and its ionization constants were determined spectrophotometrically. The fluorescent reaction of this reagent with gallium was studied. Based on this chelation reaction, a highly sensitive spectrofluorometric method was developed for the determination of gallium in a ethanol-water (3+2, V/V) medium at pH 2.3. Under these conditions, the GaⅢSABSH complex has excitation and emission maxima at 390 and 457 nm, respectively. The linear range of the method is from 0.0 to 1×10-4 g/L and the detection limit is 4×10-7 g/L of gallium when a standard additions method is used. The molar ratio of gallium to the reagent is 1∶1. Interferences were evaluated. The method was successfully applied to the determination of gallium in soil samples. Extraction with n-butyl acetate from 6 mol/L hydrochloric acid medium was used to separate gallium from the interfering elements in the soil samples.
基金the National Natural Science Foundation of China(No.20421202)for financial support.
文摘The new synthesis of 10-bromo-α-chamigrene was achieved as follows; 6-methyl-5-heptene-2-one was transformed into corresponding thioacetals, and then successively treated with Cp2Ti(P(OEt)3)2. The intermediate reacted with mono-ketal of cyclohexane-1,4-dione, and gave the carbonyl coupling product. It was then transformed into the key intermediate γ-bisabolene via deketalization, Grignard reaction, dehydration and then furnished the target molecule by polyene cyclization, with total yield 2%. All structures were confirmed by ^1H NMR and ^13C NMR. The final compound was confirmed by ^1H NMR, ^13C NMR and MS.
基金We appreciate the National Natural Science Foundations of China (No. 20372012) the Natural Science Foundations of Liaoning (No. 20032099) for the generous financial support.
文摘Photopromoted carbonylation of 1-bromo-6-chlorohexane with CO catalyzed by CuBr2 and CdI2 has been carried out under ambient conditions. The results indicate that the carbonylation proceeds with the major product of chloroester ClCH2(CH2)5COOCH3 under catalysis of CuBr2. Furthermore, the activity of the carbonylation can be improved by addition of basic additives (NaOAc, Na3PO4 or (n-C4H9)3N). Among these additives, (n-C4H9)3N is the most efficient in terms of the yield of ClCH2(CH2)5COOCH3. However, the methoxycarbonyl substituting chlorine product of BrCH2(CH2)5COOCH3 is not obtained in the presence of CdI2. This is quite different from the carbonylation of monochloroalkane.
文摘The reaction of aromatic carboxylic acid with oxalyl chloride gives rise to the corres- ponding acid chloride which without purification is treated with the sodium salt of mercapto- pyridine oxide in the presence of 2,2-azo-bisisobutyronitrile (AIBN), radical initiator to give a brominated aromatic compound. After etherification and oxidation, 5-iodovaniline was converted to trisubstituted benzene carboxylic acid which give 1-bromo-3-methoxy-4-propoxy-5-iodo- benzene by this new brominating process with a yield of 74 %.
基金This work was supported by the Natural Science Foundation of Hunan Province (No. 05JJ30016) and Science Foundation of Hengyang Normal University of China (2005A01), the Basic Research of the Hunan Province (03JZY3036)
文摘The title complex [Zn(L)(phen)(CH3OH)] (L = C8H6BrO4NS, aminomethanesulfonic acid 5-bromo-salicylaldelyde schiff base; phen = 1,10-phenanthroline) has been synthesized and characterized by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/c with a = 1.8712(3), b = 1.38008(19), c = 0.83685(12) nm, β = 97.791 (2)°, Mr = 569.72, V = 2.1411 (5) nm^3, Z= 4, Dc = 1.767 g/cm^3,μ = 3.151 mm^-1, F(000) = 1144, the final R = 0.0402 and wR = 0.0885. The central Zn(Ⅱ) is six-coordinated by one nitrogen and two oxygen atoms from the Schiff base, two nitrogen atoms from 1,10-phenanthroline and one oxygen from methanol to form a distorted octahedral coordination geometry.
文摘Sodium deoxycholate (NaDOC) could induce 1-bromo-4-(bromoacetyl) naphthalene (BBAN) to emit strong room temperature phosphorescence (RTP). Measurements of phosphore- scence spectra, peak intensity and polarization were used to investigate the solubilization of BBAN as a function of NaDOC concentration.
文摘A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.