The detailed mechanism of CuI-catalyzed C-O intramolecular coupling reaction of 2-(2-bromo-4-fluoro-phenyl)-l- cyclohexen-1-yl trifluoromethane-sulfonate was studied with the density functional theory (DFT). The g...The detailed mechanism of CuI-catalyzed C-O intramolecular coupling reaction of 2-(2-bromo-4-fluoro-phenyl)-l- cyclohexen-1-yl trifluoromethane-sulfonate was studied with the density functional theory (DFT). The geometries of the reactants, transition states, intermediates and products were optimized at the B3LYP/6-31 +G* level. Meanwhile, the single point energy of species involved in gas and solvent at B3LYP/6-31 I+G* level was individually investigated. Polarizable continuum models (PCM) were applied to the dioxane and water solutions at the same level, respectively. Results show that the rate-limiting step, M3→TS3, does not change in different solutions. However, the activation energy in a dioxane solution is lower than that in water, which explains the previous experimental results. Compared with the non-catalyzed reaction process, the activation energy of the rate- limiting step is reduced by 56.53 kJ mo1-1 in gas and 44.84 kJ mol-l in solvent, demonstrating a high catalytic efficiency of CuI.展开更多
The novel title compound(Z)-N-(4-bromo-5-ethoxy-3,5-dimethylfuran-2(5H)-yli-dene)-4-methylbenzenesulfonamide 1(C15H18BrNO4S) has been unexpectedly synthesized by the aminohalogenation reaction of ethyl 2-methy...The novel title compound(Z)-N-(4-bromo-5-ethoxy-3,5-dimethylfuran-2(5H)-yli-dene)-4-methylbenzenesulfonamide 1(C15H18BrNO4S) has been unexpectedly synthesized by the aminohalogenation reaction of ethyl 2-methylpenta-2,3-dienoate with TsNBr2,and characterized by mp,IR,1H NMR,EIMS,ESIHRMS and single-crystal X-ray diffraction.It crystallizes in mono-clinic,space group P21/c with a = 11.714(5),b = 14.106(5),c = 10.402(4) ,β = 97.298(8)°,V = 1704.9(12) 3,Mr = 388.27,Z = 4,Dc = 1.513 g/cm3,μ(MoKα) = 2.549 mm-1,F(000) = 792,the final R = 0.033 and wR = 0.062 for 3098 observed reflections(Ⅰ 〉 2σ(Ⅰ)).展开更多
The title compound has been synthesized and characterized crystallographicaUy. It is a co-crystal consisting of two different neutral zinc(H) complexes with Hbpbm (Hbpbm = 4- bromo-2-(benzimidazol-2-yl)phenol) a...The title compound has been synthesized and characterized crystallographicaUy. It is a co-crystal consisting of two different neutral zinc(H) complexes with Hbpbm (Hbpbm = 4- bromo-2-(benzimidazol-2-yl)phenol) and Hnpbm (Hnpbm = 2-(1-butylbenzimidazol-2-yl)phenol). One is a monomeric mixed-ligand complex of [Zn(bpbm)(npbm)] 1 and the other a dimer of [Zn2(npbm)4] 2 with their ratio of 2:1. Thus the overall formula for the title compound is 21.2. Adjacent 1 and 2 are connected to each other by intermolecular hydrogen bonding interactions in the lattice. The crystal data: monoclinic, space group P21/c, a = 15.0141(12), b = 20.9941(17), c = 18.4686(15) A, β = 97.445(2)°, V = 5772.4(8) A^3, Mr= 2429.68, Z = 2, Dc = 1.398 g/cm^3,μ = 1.579 -1 mm , F(000) = 2504, R = 0.0637 and wR = 0.1771 for 6464 observed reflections (I 〉 2σ(I)). The geometrical structure for 1 has also been theoretically optimized and compared with the experimental one.展开更多
The title compound 3-bromo-5-(4-chlorophenyl)-4-cyanopyrrole-N,N-dimethyl-2-amide(3) was synthesized with 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile(1) and N,N-dimethylformamide...The title compound 3-bromo-5-(4-chlorophenyl)-4-cyanopyrrole-N,N-dimethyl-2-amide(3) was synthesized with 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile(1) and N,N-dimethylformamide(2) by the α-C acylation reaction catalyzed by potassium t-butoxide, and characterized by IR, 1H-NMR and X-ray single-crystal diffraction. It crystallizes in monoclinic, space group P2(1/n)with a = 12.789(2), b = 13.783(2), c = 17.980(3) °, β = 109.230(3)°, V = 2992.5 A3, Mr = 352.62, Dc = 1.565 mg/m3, Z = 8, m = 2.924 mm-1, F(000) = 1408, the final R = 0.0424 and w R = 0.0973 for 3518 observed reflections with I 〉 2σ(I). A total of 23559 reflections were collected, of which 6242 were independent(Rint = 0.0566). The insecticidal, herbicidal and antibacterial activities of compound 3 were determined, and the experimental results showed that the mortality of 3 at the concentration of 100 ppm on the Fipronil against Linnaeus was 76.6%, the growth inhibition rate of 3 against Cynodon Dactylon under the condition of 100 ppm was 35.8% and the inhibitory activity of 3 at the concentration of 25 ppm against Fusarium graminearum reached 50.9%. Hence, the title compound has the value of further research and application prospect.展开更多
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
The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray d...The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 8.8562(15), b = 18.118(3), c = 14.055(2)A, β = 99.855(3)^o, V= 2221.9(6)A3, Z = 4, Dc = 1.496 g/cm^3,μ= 1.975 mm^-1, 2 = 0.71073A, F(000) = 1024, R = 0.0607 and wR = 0.1371.展开更多
The title compound N1-(2-(4-bromo-2-nitrophenoxy)-2-dimethyl acyloxymethyl)-5-fluorouracil(C15H13BrFN3O7, Mr = 446.19) was synthesized and structurally characterized by ^1H-NMR, -(13)C-NMR, ESI-MS and single-c...The title compound N1-(2-(4-bromo-2-nitrophenoxy)-2-dimethyl acyloxymethyl)-5-fluorouracil(C15H13BrFN3O7, Mr = 446.19) was synthesized and structurally characterized by ^1H-NMR, -(13)C-NMR, ESI-MS and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P1, with a = 8.3325(6), b = 10.1808(13), c = 11.8194(16) A, α = 73.194(12), β= 72.351(9), γ = 89.509(8)o, V = 911.2(2) A^3, Z = 2, T = 300.79(10) K, μ(Cu Kα) = 3.578 mm^-1, Dc = 1.626 g/cm3, F(000) = 448.0, GOF = 1.060, 5723 reflections measured(8.232≤2θ≤139.592°), 3339 unique(Rint = 0.0184, Rsigma = 0.0254) which were used in all calculations. The final R = 0.0517(I 〉 2s(I)) and wR = 0.1494(all data). Hydrogen bonds and π-π interactions together stabilize the structure of the molecule. The preliminary biological test shows that the title compound has good antitumor activity against A549 in vitro and lower toxicity to normal cells.展开更多
2-Bromo-4-methylphenol was synthesized from 4-methylphenol by oxidative bromination at the low temperature,with a yield of 93%.The product was characterized by IR and ()1H NMR spectroscopy.The optimum conditions of ...2-Bromo-4-methylphenol was synthesized from 4-methylphenol by oxidative bromination at the low temperature,with a yield of 93%.The product was characterized by IR and ()1H NMR spectroscopy.The optimum conditions of the reaction were:reaction temperature was-5~-10℃,the mol ratio of C7H8O:H2O2 was 1:0.85,reaction time was 4h and agitation rate was 1000 r/min.展开更多
Ethyl 3-alkyl-4-hydroxy-2-thioxothiazolidine-4-carboxylates were prepared in excellent yields from the reaction of corresponding primary amines with carbon disulfide and ethyl 3-bromo-2-oxopropanoate in the presence o...Ethyl 3-alkyl-4-hydroxy-2-thioxothiazolidine-4-carboxylates were prepared in excellent yields from the reaction of corresponding primary amines with carbon disulfide and ethyl 3-bromo-2-oxopropanoate in the presence of anhydrous potassium phosphate in DMF at room temperature within 1 h. The structures of the highly functionalized products were corroborated spectroscopically (IR, ^1H NMR, ^13C NMR, EI-MS) and by elemental analyses. A plausible mechanism for such type of cyclization was proposed.展开更多
A new asymmetric bidentate copper(Ⅱ) complex,CuL 2(HL=2-((E)-(4-bromophenylimino)methyl)-6-bromo-4-chlorophenol),has been synthesized and characterized by elemental analyses and single-crystal X-ray diffrac...A new asymmetric bidentate copper(Ⅱ) complex,CuL 2(HL=2-((E)-(4-bromophenylimino)methyl)-6-bromo-4-chlorophenol),has been synthesized and characterized by elemental analyses and single-crystal X-ray diffraction.The complex crystallizes in the monoclinic space group P2 1 /c with a=11.218(3),b=9.355(3),c=13.449(4),β=108.722(4)°,V=1336.8(6)3,Z=2,Dc=2.008 g/cm 3,μ(MoKα)=7.024 mm-1,F(000)=806,S=0.999,the final R=0.0342 and wR=0.0641for2611observed reflections (I〉2σ(I)).The central copper(Ⅱ) is four-coordinate and bonds to two nitrogen and two oxygen atoms from two Schiff base ligands.The complex is linked into a two-dimensional supramolecular structure by weak intermolecular interactions.In addition,DNA-binding properties of the metal complex were investigated using spectrometric titrations and viscosity measurements.The results show that the complex binds with calf-thymus DNA(CT-DNA),presumably via a partial intercalative mode.The intrinsic binding constant of the Cu(Ⅱ) complex with DNA is 7.335×10 3 M-1.展开更多
In the presence of In/CuCl, ethyl 4-bromo-4,4-difluoro-3-oxo-2-(triphenylphosphoranylidene)butanoate reacted with various aldehydes in aqueous medium at room temperature to give the a,a-difluorinated β-hydroxy carb...In the presence of In/CuCl, ethyl 4-bromo-4,4-difluoro-3-oxo-2-(triphenylphosphoranylidene)butanoate reacted with various aldehydes in aqueous medium at room temperature to give the a,a-difluorinated β-hydroxy carbonyl compounds. Furthermore, treating Reformatsky addition compounds with 1 equiv, of sodium hydroxide in the mixture of tetrahydrofuran and water afforded gem-difluoromethylenated 2-triphenylphosphoranylidene δ-lactones in excellent yields.展开更多
Composition of bromine and nitric acid in concentrated sulfuric acid is effective for bromination of strongly deactivated aromatic compounds and for nitration and bromination of moderately deactivated compounds in one...Composition of bromine and nitric acid in concentrated sulfuric acid is effective for bromination of strongly deactivated aromatic compounds and for nitration and bromination of moderately deactivated compounds in one stage. The question why brominating agent is more reactive than nitrating agent in relation to strongly deactivated aromatic compounds and is less reactive in relation to moderate deactivated ones is discussed.展开更多
Action of bromine in concentrated nitric acid allows carrying out mono- and polybromination of moderately deactivated aromatic compounds. 4-Chloronitrobenzene and isophthalic acid turnes into 3-bromo-4-chloronitrobenz...Action of bromine in concentrated nitric acid allows carrying out mono- and polybromination of moderately deactivated aromatic compounds. 4-Chloronitrobenzene and isophthalic acid turnes into 3-bromo-4-chloronitrobenzene and 5-bromoisophthalic acid at reaction with bromine in concentrated nitric acid at 20°C whereas in absence of bromine in the same conditions 4-chloro-1, 3-dinitrobenzene and 5-nitroisophthalic acid are formed accordingly. Presence of bromine in concentrated nitric acid changes nitrating capacity to brominating one. Terephthalic acid and phthalic anhydride at heating with bromine in concentrated nitric acid can be transformed to appropriating tetrabromo substituted compounds.展开更多
Organophosphorus pesticides (OPs) are one of the most regular pollutants and frequently detected in the contaminated sites, so developing an efficient method for the treatment of OPs is highly required. The aim of t...Organophosphorus pesticides (OPs) are one of the most regular pollutants and frequently detected in the contaminated sites, so developing an efficient method for the treatment of OPs is highly required. The aim of the present study was to compare the effectiveness of persulfate (PS) activation and Fenton reaction in remediating the soil polluted with OPs. The polluted soil used in this study was sampled from an abandoned insecticide factory in Nantong, Jiangsu Province of China, mainly containing chloropyrifos (CP) and 4-bromo-2-chlorophenol (BCP, the raw material of profenofos) with total concentration of about 30 000 mg kg- 1. The results showed that both BCP and CP were efficiently degraded by base activation of PS, and increasing the ratio of NaOH/PS enhanced CP degradation, but slightly decreased BCP degradation. The greatest degradation rates for CP and BCP were 92% and 97%, respectively, with 7.0 tool L-1 NaOH and 0.21 tool L-1 PS and a soil-to-liquid ratio of 1:1. Furthermore, ferrous iron activation of PS also degraded BCP efficiently, but only 60% of CP was degraded under the same reaction conditions. These results indicated that base activation of PS was more feasible than Fe2+ activation and Fenton reaction in remediating the soil polluted with OPs. The high degradation rate for CP may be linked to the initial hydrolyzation of CP by base to 3,5,6-trichloro-2-pyridinol, which can be further rapidly degraded by free radicals generated from base activation of PS.展开更多
A new conjugated copolymer (PTST-DyOXD) derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis(5-bromo-2- thienyl)-silole (TST) and 2,5-bis(4-ethynylphenyl)-l,3,4-oxadiazole (DyOXD) was synthesized by Pd(0)-cataly...A new conjugated copolymer (PTST-DyOXD) derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis(5-bromo-2- thienyl)-silole (TST) and 2,5-bis(4-ethynylphenyl)-l,3,4-oxadiazole (DyOXD) was synthesized by Pd(0)-catalyzed Sonogashira coupling reaction. For comparison, another copolymer without acetenyl group (PTST-OXD) was also synthesized by Pd(0)-catalyzed Suzuki coupling reaction. Chemical structures and optoelectronic properties of the copolymers were characterized by IH NMR, 13C NMR, IR, UV-vis absorption, photoluminescence and cyclic voltammetry. The number-average molecular weight (Mn) is 4010 Da for PTST-DyOXD and 3890 Da for PTST-OXD, respectively. The thermogravimetric analysis (TGA) measurements show that they have good thermal stability with decomposition temperature at 312 and 318 ~C, respectively. The optical band gap is 2.21 eV for PTST-DyOXD and 2.10 eV for PTST-OXD based on the absorption onset. CV analysis revealed the LUMO level of PTST-DyOXD is -3.04 eV, lower than that of PTST-OXD (about -2.89 eV), which is attributed to the introduction of acetylene group in PTST-DyOXD, increasing the system of the conjugate chain length.展开更多
文摘The detailed mechanism of CuI-catalyzed C-O intramolecular coupling reaction of 2-(2-bromo-4-fluoro-phenyl)-l- cyclohexen-1-yl trifluoromethane-sulfonate was studied with the density functional theory (DFT). The geometries of the reactants, transition states, intermediates and products were optimized at the B3LYP/6-31 +G* level. Meanwhile, the single point energy of species involved in gas and solvent at B3LYP/6-31 I+G* level was individually investigated. Polarizable continuum models (PCM) were applied to the dioxane and water solutions at the same level, respectively. Results show that the rate-limiting step, M3→TS3, does not change in different solutions. However, the activation energy in a dioxane solution is lower than that in water, which explains the previous experimental results. Compared with the non-catalyzed reaction process, the activation energy of the rate- limiting step is reduced by 56.53 kJ mo1-1 in gas and 44.84 kJ mol-l in solvent, demonstrating a high catalytic efficiency of CuI.
文摘The novel title compound(Z)-N-(4-bromo-5-ethoxy-3,5-dimethylfuran-2(5H)-yli-dene)-4-methylbenzenesulfonamide 1(C15H18BrNO4S) has been unexpectedly synthesized by the aminohalogenation reaction of ethyl 2-methylpenta-2,3-dienoate with TsNBr2,and characterized by mp,IR,1H NMR,EIMS,ESIHRMS and single-crystal X-ray diffraction.It crystallizes in mono-clinic,space group P21/c with a = 11.714(5),b = 14.106(5),c = 10.402(4) ,β = 97.298(8)°,V = 1704.9(12) 3,Mr = 388.27,Z = 4,Dc = 1.513 g/cm3,μ(MoKα) = 2.549 mm-1,F(000) = 792,the final R = 0.033 and wR = 0.062 for 3098 observed reflections(Ⅰ 〉 2σ(Ⅰ)).
基金This work was supported by the Natural Science Foundation of Guangdong Province (No. 06301028)
文摘The title compound has been synthesized and characterized crystallographicaUy. It is a co-crystal consisting of two different neutral zinc(H) complexes with Hbpbm (Hbpbm = 4- bromo-2-(benzimidazol-2-yl)phenol) and Hnpbm (Hnpbm = 2-(1-butylbenzimidazol-2-yl)phenol). One is a monomeric mixed-ligand complex of [Zn(bpbm)(npbm)] 1 and the other a dimer of [Zn2(npbm)4] 2 with their ratio of 2:1. Thus the overall formula for the title compound is 21.2. Adjacent 1 and 2 are connected to each other by intermolecular hydrogen bonding interactions in the lattice. The crystal data: monoclinic, space group P21/c, a = 15.0141(12), b = 20.9941(17), c = 18.4686(15) A, β = 97.445(2)°, V = 5772.4(8) A^3, Mr= 2429.68, Z = 2, Dc = 1.398 g/cm^3,μ = 1.579 -1 mm , F(000) = 2504, R = 0.0637 and wR = 0.1771 for 6464 observed reflections (I 〉 2σ(I)). The geometrical structure for 1 has also been theoretically optimized and compared with the experimental one.
基金supported by the National Natural Science Foundation of China(No.21272086)
文摘The title compound 3-bromo-5-(4-chlorophenyl)-4-cyanopyrrole-N,N-dimethyl-2-amide(3) was synthesized with 4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile(1) and N,N-dimethylformamide(2) by the α-C acylation reaction catalyzed by potassium t-butoxide, and characterized by IR, 1H-NMR and X-ray single-crystal diffraction. It crystallizes in monoclinic, space group P2(1/n)with a = 12.789(2), b = 13.783(2), c = 17.980(3) °, β = 109.230(3)°, V = 2992.5 A3, Mr = 352.62, Dc = 1.565 mg/m3, Z = 8, m = 2.924 mm-1, F(000) = 1408, the final R = 0.0424 and w R = 0.0973 for 3518 observed reflections with I 〉 2σ(I). A total of 23559 reflections were collected, of which 6242 were independent(Rint = 0.0566). The insecticidal, herbicidal and antibacterial activities of compound 3 were determined, and the experimental results showed that the mortality of 3 at the concentration of 100 ppm on the Fipronil against Linnaeus was 76.6%, the growth inhibition rate of 3 against Cynodon Dactylon under the condition of 100 ppm was 35.8% and the inhibitory activity of 3 at the concentration of 25 ppm against Fusarium graminearum reached 50.9%. Hence, the title compound has the value of further research and application prospect.
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This work was supported by the National Natural Science Foundation of China (No. 20472072 and 20332060)the CAS Academician Foundation of Zhejiang Province
文摘The title compound 4-bromo-5-ethoxy-3-methyl-5-(naphthalen-l-yl)-l-tosyl-lH- pyrrol-2(5H)-one 1 (C24H22BrNO4S, Mr = 500.40) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 8.8562(15), b = 18.118(3), c = 14.055(2)A, β = 99.855(3)^o, V= 2221.9(6)A3, Z = 4, Dc = 1.496 g/cm^3,μ= 1.975 mm^-1, 2 = 0.71073A, F(000) = 1024, R = 0.0607 and wR = 0.1371.
基金Gansu Province Science and Technology Bureau Program Funds(144FKCA065)
文摘The title compound N1-(2-(4-bromo-2-nitrophenoxy)-2-dimethyl acyloxymethyl)-5-fluorouracil(C15H13BrFN3O7, Mr = 446.19) was synthesized and structurally characterized by ^1H-NMR, -(13)C-NMR, ESI-MS and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P1, with a = 8.3325(6), b = 10.1808(13), c = 11.8194(16) A, α = 73.194(12), β= 72.351(9), γ = 89.509(8)o, V = 911.2(2) A^3, Z = 2, T = 300.79(10) K, μ(Cu Kα) = 3.578 mm^-1, Dc = 1.626 g/cm3, F(000) = 448.0, GOF = 1.060, 5723 reflections measured(8.232≤2θ≤139.592°), 3339 unique(Rint = 0.0184, Rsigma = 0.0254) which were used in all calculations. The final R = 0.0517(I 〉 2s(I)) and wR = 0.1494(all data). Hydrogen bonds and π-π interactions together stabilize the structure of the molecule. The preliminary biological test shows that the title compound has good antitumor activity against A549 in vitro and lower toxicity to normal cells.
文摘2-Bromo-4-methylphenol was synthesized from 4-methylphenol by oxidative bromination at the low temperature,with a yield of 93%.The product was characterized by IR and ()1H NMR spectroscopy.The optimum conditions of the reaction were:reaction temperature was-5~-10℃,the mol ratio of C7H8O:H2O2 was 1:0.85,reaction time was 4h and agitation rate was 1000 r/min.
基金Project supported by the National Natural Science Foundation of China (Nos. 20172006 and 20472008).
文摘Ethyl 3-alkyl-4-hydroxy-2-thioxothiazolidine-4-carboxylates were prepared in excellent yields from the reaction of corresponding primary amines with carbon disulfide and ethyl 3-bromo-2-oxopropanoate in the presence of anhydrous potassium phosphate in DMF at room temperature within 1 h. The structures of the highly functionalized products were corroborated spectroscopically (IR, ^1H NMR, ^13C NMR, EI-MS) and by elemental analyses. A plausible mechanism for such type of cyclization was proposed.
文摘A new asymmetric bidentate copper(Ⅱ) complex,CuL 2(HL=2-((E)-(4-bromophenylimino)methyl)-6-bromo-4-chlorophenol),has been synthesized and characterized by elemental analyses and single-crystal X-ray diffraction.The complex crystallizes in the monoclinic space group P2 1 /c with a=11.218(3),b=9.355(3),c=13.449(4),β=108.722(4)°,V=1336.8(6)3,Z=2,Dc=2.008 g/cm 3,μ(MoKα)=7.024 mm-1,F(000)=806,S=0.999,the final R=0.0342 and wR=0.0641for2611observed reflections (I〉2σ(I)).The central copper(Ⅱ) is four-coordinate and bonds to two nitrogen and two oxygen atoms from two Schiff base ligands.The complex is linked into a two-dimensional supramolecular structure by weak intermolecular interactions.In addition,DNA-binding properties of the metal complex were investigated using spectrometric titrations and viscosity measurements.The results show that the complex binds with calf-thymus DNA(CT-DNA),presumably via a partial intercalative mode.The intrinsic binding constant of the Cu(Ⅱ) complex with DNA is 7.335×10 3 M-1.
基金Project supported by the National Natural Science Foundation of China (NNSFC) (Nos. 20972050, 21172148).
文摘In the presence of In/CuCl, ethyl 4-bromo-4,4-difluoro-3-oxo-2-(triphenylphosphoranylidene)butanoate reacted with various aldehydes in aqueous medium at room temperature to give the a,a-difluorinated β-hydroxy carbonyl compounds. Furthermore, treating Reformatsky addition compounds with 1 equiv, of sodium hydroxide in the mixture of tetrahydrofuran and water afforded gem-difluoromethylenated 2-triphenylphosphoranylidene δ-lactones in excellent yields.
文摘Composition of bromine and nitric acid in concentrated sulfuric acid is effective for bromination of strongly deactivated aromatic compounds and for nitration and bromination of moderately deactivated compounds in one stage. The question why brominating agent is more reactive than nitrating agent in relation to strongly deactivated aromatic compounds and is less reactive in relation to moderate deactivated ones is discussed.
文摘Action of bromine in concentrated nitric acid allows carrying out mono- and polybromination of moderately deactivated aromatic compounds. 4-Chloronitrobenzene and isophthalic acid turnes into 3-bromo-4-chloronitrobenzene and 5-bromoisophthalic acid at reaction with bromine in concentrated nitric acid at 20°C whereas in absence of bromine in the same conditions 4-chloro-1, 3-dinitrobenzene and 5-nitroisophthalic acid are formed accordingly. Presence of bromine in concentrated nitric acid changes nitrating capacity to brominating one. Terephthalic acid and phthalic anhydride at heating with bromine in concentrated nitric acid can be transformed to appropriating tetrabromo substituted compounds.
基金supported by the National Key Basic Research Program of China (No. 2013CB934303)the Environmental Protection Program of Jiangsu Province of China (No. 2015011)the Youth Innovation Promotion Association of Chinese Academy of Sciences (No. 2014270)
文摘Organophosphorus pesticides (OPs) are one of the most regular pollutants and frequently detected in the contaminated sites, so developing an efficient method for the treatment of OPs is highly required. The aim of the present study was to compare the effectiveness of persulfate (PS) activation and Fenton reaction in remediating the soil polluted with OPs. The polluted soil used in this study was sampled from an abandoned insecticide factory in Nantong, Jiangsu Province of China, mainly containing chloropyrifos (CP) and 4-bromo-2-chlorophenol (BCP, the raw material of profenofos) with total concentration of about 30 000 mg kg- 1. The results showed that both BCP and CP were efficiently degraded by base activation of PS, and increasing the ratio of NaOH/PS enhanced CP degradation, but slightly decreased BCP degradation. The greatest degradation rates for CP and BCP were 92% and 97%, respectively, with 7.0 tool L-1 NaOH and 0.21 tool L-1 PS and a soil-to-liquid ratio of 1:1. Furthermore, ferrous iron activation of PS also degraded BCP efficiently, but only 60% of CP was degraded under the same reaction conditions. These results indicated that base activation of PS was more feasible than Fe2+ activation and Fenton reaction in remediating the soil polluted with OPs. The high degradation rate for CP may be linked to the initial hydrolyzation of CP by base to 3,5,6-trichloro-2-pyridinol, which can be further rapidly degraded by free radicals generated from base activation of PS.
基金The authors are grateful to financial support from the National Natural Science Foundation of China,the East China University of Science and Technology
文摘A new conjugated copolymer (PTST-DyOXD) derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis(5-bromo-2- thienyl)-silole (TST) and 2,5-bis(4-ethynylphenyl)-l,3,4-oxadiazole (DyOXD) was synthesized by Pd(0)-catalyzed Sonogashira coupling reaction. For comparison, another copolymer without acetenyl group (PTST-OXD) was also synthesized by Pd(0)-catalyzed Suzuki coupling reaction. Chemical structures and optoelectronic properties of the copolymers were characterized by IH NMR, 13C NMR, IR, UV-vis absorption, photoluminescence and cyclic voltammetry. The number-average molecular weight (Mn) is 4010 Da for PTST-DyOXD and 3890 Da for PTST-OXD, respectively. The thermogravimetric analysis (TGA) measurements show that they have good thermal stability with decomposition temperature at 312 and 318 ~C, respectively. The optical band gap is 2.21 eV for PTST-DyOXD and 2.10 eV for PTST-OXD based on the absorption onset. CV analysis revealed the LUMO level of PTST-DyOXD is -3.04 eV, lower than that of PTST-OXD (about -2.89 eV), which is attributed to the introduction of acetylene group in PTST-DyOXD, increasing the system of the conjugate chain length.