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Mengdi Zhao - One of the best experts on this subject based on the ideXlab platform.
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visible light driven oxidative mono and dibromination of benzylic sp3 c h bonds with Potassium Bromide oxone at room temperature
Synthesis, 2018Co-Authors: Mengdi ZhaoAbstract:Benzylic sp3 C–H bonds have been successfully brominated with Potassium Bromide by using Oxone as an oxidant in water/dichloromethane under visible light at room temperature. Toluene, ethylbenzene and other alkylbenzenes bearing an electron-withdrawing group, such as Br, Cl, COMe, CO2Et, CO2H, CN or NO2, provide the corresponding benzylic monoBromides in good to excellent yields in this reaction. DiBromides can also be produced in the presence of excess Potassium Bromide in a prolonged reaction time. Control of the illuminance of visible light (~500 lux) is crucial to achieving both high yield and high selectivity in these brominations. Mono- and difluorides can be conveniently prepared through nucleophilic substitutions of the benzylic Bromides with Potassium fluoride.
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Visible-Light-Driven Oxidative Mono- and Dibromination of Benzylic sp3 C–H Bonds with Potassium Bromide/Oxone at Room Temperature
Synthesis, 2018Co-Authors: Mengdi ZhaoAbstract:Benzylic sp3 C–H bonds have been successfully brominated with Potassium Bromide by using Oxone as an oxidant in water/dichloromethane under visible light at room temperature. Toluene, ethylbenzene and other alkylbenzenes bearing an electron-withdrawing group, such as Br, Cl, COMe, CO2Et, CO2H, CN or NO2, provide the corresponding benzylic monoBromides in good to excellent yields in this reaction. DiBromides can also be produced in the presence of excess Potassium Bromide in a prolonged reaction time. Control of the illuminance of visible light (~500 lux) is crucial to achieving both high yield and high selectivity in these brominations. Mono- and difluorides can be conveniently prepared through nucleophilic substitutions of the benzylic Bromides with Potassium fluoride.
Si Xue-zhi - One of the best experts on this subject based on the ideXlab platform.
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Study on extraction separation and enrichment of germanium in ammonia sulfate-Potassium Bromide-n-propyl alcohol system
Chinese Journal of Analysis Laboratory, 2012Co-Authors: Si Xue-zhiAbstract:The behavior and conditions of extraction separation and concentration of germanium from other metal ions in ammonia sulfate-Potassium Bromide-n-propyl alcohol system were studied.The results showed that the n-propyl alcohol-water solution could be well divided into two phases by the action of ammonia sulfate.The associated complex [GeBr62-][C3H7OH2+]2 formed with C3H7OH2+ and GeBr62-combined by Ge4+ and Potassium Bromide could be completely extracted during this process.Ge4+ could be quantiatively separated from Ni2+,Pb2+,Cr3+,Co2+,Fe3+,Al3+,Mg2+,Ag+,Bi3+,Cu2+,W(Ⅵ) and V(Ⅴ) by the extraction process.The value of extraction efficiency of Ge4+ can reach 97.7% when the concentration of n-propyl alcohol is 30%(V/V),the Potassium Bromide is 7.0×10-3mol/L,and the ammonia sulfate in solution is 0.20 g/mL.
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Study on extraction separation and enrichment of iridium by ethanol-Potassium Bromide in the presence of ammonium sulphate
Chinese Journal of Analysis Laboratory, 2009Co-Authors: Si Xue-zhiAbstract:The behavior and conditions of extraction separation and concentration of iridium from other metal ions in ethanol-Potassium Bromide-ammonium sulphate system were studied.The results showed that the ethanol-water solution could be well divided into two phases with the action of ammonium sulphate.C2H5OH2+ is associated with [IrBr62-](form the combination of Ir(Ⅳ) and Potassium Bromide) to form a complex [IrBr62-] [C2H5OH2+]2 which could be completely extracted during this process,and Ir(Ⅳ) could be quantitatively separated from Ga(Ⅲ),Al(Ⅲ),Cr(Ⅲ),Mo(Ⅵ),Fe(Ⅲ),Ni(Ⅱ),Zn(Ⅱ),Co(Ⅱ),Mn(Ⅱ),V(Ⅴ),Ag(Ⅰ),Ru(Ⅲ) and Rh(Ⅲ) by extraction.The extraction efficiency of Ir(Ⅳ) is higher than 99.5% when the concentrations of ethanol,Potassium Bromide and ammonium sulphate in solution(pH 3) are 30%(V/V-1),4.0×10-3 mol/L and 0.3 g/mL,respectively.
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Study on floatation separation of gold(III) with Potassium Bromide-tetrabutyl ammonium Bromide-water system
Metallurgical Analysis, 2008Co-Authors: Si Xue-zhiAbstract:The flotation separation behavior of Au(Ⅲ) in Potassium Bromide-tetrabutyl ammonium Bromide system and the conditions for the separation of Au(Ⅲ) from other metal ions are studied.The results showed that Au(Ⅲ) with Potassium Bromide and tetrabutyl ammonium Bromide formed a ternary associated complex.which was floated on the upper layer of salt-water to make the system divide into both liquid and solid phases with a distinct boundary.Au(Ⅲ) could be quantiatively separated from Ru(Ⅲ),Fe(Ⅲ),Al(Ⅲ),Cd(Ⅱ),Co(Ⅱ),Mn(Ⅱ),Zn(Ⅱ),Ni(Ⅱ),Cr(Ⅲ) and Pt(Ⅳ) in the concentrations of 2.5×10-2 mol/L Potassium Bromide and 2.0×10-3 mol/L tetrabutyl ammonium Bromide at pH 2.0.The method has been used for the separation and spectrophotometric determination of Au(Ⅲ) in synthetic water sample with satisfactory results.
M Vairamani - One of the best experts on this subject based on the ideXlab platform.
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an efficient bromination of alkenes using cerium iv ammonium nitrate can and Potassium Bromide
Tetrahedron, 2001Co-Authors: Vijay Nair, Sreeletha B Panicker, Anu Augustine, Tesmol G George, Siji Thomas, M VairamaniAbstract:Abstract Bromination of alkenes using a combination of Potassium Bromide and cerium(iv) ammonium nitrate (CAN) in a two phase system consisting of water and dichloromethane affords the corresponding diBromides in excellent yield. The reaction most likely involves the addition of the bromine radical generated from Bromide ion by CAN and subsequent formation of the diBromide.
Jiang Heng - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of 1-Bromobutane by Improved Potassium Bromide-Concentrated Sulfuric Acid Method
Journal of Salt and Chemical Industry, 2008Co-Authors: Jiang HengAbstract:1-Bromobutane was synthesized from Potassium Bromide and n-butyl alcohol by superadding concentrated sulfuric acid in water.Various affecting factors were investigated.The optimal conditions were n-butyl alcohol 0.16mol,Potassium Bromide 0.18ml,initial amount of concentrated sulfuric acid 4mL,additional amount 12mL,refluxed for 5h,and the separated yield was up to 88.4%.After the waste liquid was disposed using calcium oxide,calcium sulfate and Potassium sulfate were got.Raw product was analyzed by GC,and no by-product was detected.Pure product was characterized by index of refraction and IR.
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Synthesis of 1-bromododecane using Potassium Bromide-concentrated sulfuric acid method
Science & Technology in Chemical Industry, 2007Co-Authors: Jiang HengAbstract:1-Bromododecane was synthesized from Potassium Bromide which is the by-product of synthesizing 2-hydroxy-4-n-dodecyloxybenzophenone and n-dodecyl alcohol using concentrated sulfuric acid as catalyst.By investigating the reaction condition,the experimental result showed that the optimal conditions are Potassium Bromide 0.1 mol,n-dodecyl alcohol 0.08 mol,concentrated sulfuric acid 6 mL,H2O 2.5 mL,refluxing for 4 h,the separated yield is high up to 92.5%.Raw product was analyzed by GC and no by-product was detected almost.Pure product was characterized by IR and index of refraction.
Fatemeh Komaki - One of the best experts on this subject based on the ideXlab platform.
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electrophilic bromination ofalkenes alkynes and aromatic amines with Potassium Bromide orthoperiodicacid under mild conditions
Synthesis, 2009Co-Authors: Ardeshir Khazaei, Mohammad Ali Zolfigol, Eskandar Kolvari, Nadiya Koukabi, Hamid Soltani, Fatemeh KomakiAbstract:Bromination of alkenes, alkynes, and aromatic amines has efficiently been carried out at room temperature in short reaction times using Potassium Bromide/orthoperiodic acid in dichloromethane-water (1:1) to prepare the corresponding bromo compounds with excellent yields.
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Electrophilic Bromination ofAlkenes, Alkynes, and Aromatic Amines with Potassium Bromide/OrthoperiodicAcid under Mild Conditions
Synthesis, 2009Co-Authors: Ardeshir Khazaei, Mohammad Ali Zolfigol, Eskandar Kolvari, Nadiya Koukabi, Hamid Soltani, Fatemeh KomakiAbstract:Bromination of alkenes, alkynes, and aromatic amines has efficiently been carried out at room temperature in short reaction times using Potassium Bromide/orthoperiodic acid in dichloromethane-water (1:1) to prepare the corresponding bromo compounds with excellent yields.