14348-41-5Relevant articles and documents
The Bromination of p-Hydroxybenzoic Acid in Aqueous Solution. Reaction via the Minor p-Carboxyphenoxide Anion Tautomer
Tee, Oswald S.,Iyengar, N. Rani,Kraus, Brigitte
, p. 973 - 976 (1985)
The kinetics of bromination of p-hydroxybenzoic acid have been measured in aqueous solution in the pH range 0-6.From the pH-log rate profile the reactive species appear to be the free acid (pH 5).However, the reactivity attributable to the monoanion is about 9 times higher than that predicted by a Hammett plot for the bromination of p-substituted phenols.This deviation is described to reaction via the tautomeric p-carboxyphenoxide monoanion which is present to the extent of 1 in 3100.Support for this proposal comes from related studies on ethyl p-hydroxybenzate, 3-bromo-4-hydroxybenzoic acid, and p-methoxybenzoic acid.In particular, the 3-bromo-4-hydroxybenzoate anion appears to be 5200 times more reactive than predicted and twice as reactive as the p-hydroxybenzoate anion.These anomalies are removed if reaction occurs via the minor tautomeric anion.
Oxidative bromination in a liquid-liquid two-phase system to synthesize organic intermediates: 2-Bromophenol, 2,6-dibromophenol, and 2-bromo-4-methylphenol
Mukhopadhyay, Sudip,Ananthakrishnan,Chandalia, Sampatraj B.
, p. 451 - 454 (1999)
An alternative manufacturing process-scheme was developed to synthesize 2-bromophenol and 2,6-dibromophenol involving oxidative bromination of a substrate protected in the para position in a two-phase system followed by deprotection involving decarboxylation. Thus, selective oxidative bromination of 4-hydroxybenzoic acid in ethylenedichloride with HBr-H2O2, and subsequent decarboxylation in quinoline gave 90-95% yield to the mono- or dibromophenol depending upon the mol ratio of HBr:H2O2 employed in the oxidative bromination. Similarly, 4-methylphenol under identical reaction conditions gave 99.6% selectivity to 2-bromo-4-methylphenol at 89% conversion ratio of 4-methylphenol.
A convenient and efficient H2SO4-promoted regioselective monobromination of phenol derivatives using N-bromosuccinimide
Wu, Yong-Qi,Lu, Hai-Jia,Zhao, Wen-Ting,Zhao, Hong-Yi,Lin, Zi-Yun,Zhang, Dong-Feng,Huang, Hai-Hong
supporting information, p. 813 - 822 (2020/02/15)
A convenient, rapid H2SO4-promoted regioselective monobromination reaction with N-bromosuccinimide was developed. The desired para-monobrominated or ortho-monobrominated products of phenol derivatives were obtained in good to excellent yields with high selectivity. Regioselective chlorination and iodination were also achieved in the presence of H2SO4 using N-chlorosuccinimide and N-iodosuccinimide, respectively.
A where the shall he loni intermediate and its preparation method
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Paragraph 0096; 0097, (2019/04/04)
The present invention provides a where the shall he loni intermediate and its preparation method, the where the shall he loni intermediate by compound 8 in the sodium methoxide or metal lithium, sodium, potassium and the like under the action 9 acidifying the resulting: Wherein X fluorine, chlorine, bromine, move in the halogen, R3 is lithium, sodium, potassium and the like metal. The invention conducive to product quality control, the reaction condition is more simple, moderate, environmental protection, high requirements on equipment, each step the reaction yield is higher.
An efficient one pot method for synthesis of carboxylic acids from nitriles using recyclable ionic liquid [bmim]HSO4 Dedicated to my mentor Professor (Mrs.) Krishna Misra on her 76th birthday
Kumar, Satyanand,Dixit, Sandeep Kumar,Awasthi, Satish Kumar
supporting information, p. 3802 - 3804 (2014/07/07)
Environmentally benign ionic liquid [bmim]HSO4 was found suitable for conversion of nitriles into carboxylic acids under mild conditions with excellent purity.
Peroxidative bromination and oxygenation of organic compounds: Synthesis, X-ray crystal structure and catalytic implications of mononuclear and binuclear oxovanadium(V) complexes containing Schiffbase ligands
Si, Tapan Kumar,Drew, Michael G.B.,Mukherjea, Kalyan Kumar
experimental part, p. 2286 - 2293 (2011/10/11)
Treatment of of (R,R)-N,N-salicylidene cyclohexane 1,2-diamine(H 2L1) in methanol with aqueous NH4VO3 solution in perchloric acid medium affords the mononuclear oxovanadium(V) complex [VOL1(MeOH)]·ClO4 (1) as deep blue solid while the treatment of same solution of (R,R)-N,N-salicylidene cyclohexane 1,2-diamine(H2L1) with aqueous solution of VOSO 4 leads to the formation of di-(μ-oxo) bridged vanadium(V) complex [VO2L2]2 (2) as green solid where HL 2 = (R,R)-N-salicylidene cyclohexane 1,2-diamine. The ligand HL 2 is generated in situ by the hydrolysis of one of the imine bonds of HL1 ligand during the course of formation of complex [VO 2L2]2 (2). Both the compounds have been characterized by single crystal X-ray diffraction as well as spectroscopic methods. Compounds 1 and 2 are to act as catalyst for the catalytic bromide oxidation and C-H bond oxidation in presence of hydrogen peroxide. The representative substrates 2,4-dimethoxy benzoic acid and para-hydroxy benzoic acids are brominated in presence of H2O2 and KBr in acid medium using the above compounds as catalyst. The complexes are also used as catalyst for C-H bond activation of the representative hydrocarbons toluene, ethylbenzene and cyclohexane where hydrogen peroxide acts as terminal oxidant. The yield percentage and turnover number are also quite good for the above catalytic reaction. The oxidized products of hydrocarbons have been characterized by GC Analysis while the brominated products have been characterized by 1H NMR spectroscopic studies.
Regioselective and high-yielding bromination of phenols and anilins using N-bromosaccharin and amberlyst-15
Baharfar,Alinezhad,Azimi,Salehian
experimental part, p. 863 - 865 (2012/04/23)
A regioselective and facile conversion method for bromination of anilines and phenols using N-bromosaccharine in the presence of a catalytic amount of Amberlyst-15 lead to enhancement of the reaction rate and yielded brominated products in good to excellent yields and short reaction times.
An efficient regioselective NBS aromatic bromination in the presence of an ionic liquid
Pingali, Subramanya R.K.,Madhav, Monika,Jursic, Branko S.
experimental part, p. 1383 - 1385 (2010/04/25)
A simple, efficient, and rapid method was developed for high-yielding regioselective monobromination of activated aromatic compounds using NBS in combination with ionic liquid 1-butyl-1-methylimidazolium bromide ([Bmim]Br) or dioxane. The ionic liquid is recyclable and can be reused with minimal loss in the catalytic efficiency if the ionic liquid is rapidly microwaved prior to reactions.
Efficient, rapid, and regioselective bromination of phenols and anilines with N-bromosaccharin using tungstophosphoric acid as a heterogeneous recyclable catalyst
Alinezhad, Heshmatollah,Tavakkoli, Sahar Mohseni,Salehian, Fatemeh
experimental part, p. 3226 - 3232 (2010/12/24)
A simple, efficient, and rapid method for high-yielding regioselective mono bromination of phenols and anilines has been achieved by treatment with N-bromasaccharin in the presence of a catalytic amount of tungstophosphoric acid. Copyright Taylor & Francis Group, LLC.
Synthesis and mesomorphic properties of esters derived from alkanediols
Maksimenko,Novikova,Kondrat'Eva,Kuz'Min,Ognichenko,Yarkova
experimental part, p. 1773 - 1780 (2009/09/29)
New alkane-α,ω-diyl esters, propane-1,3-diyl and butane-1,4-diyl bis[4-(4-alkoxybenzoyloxy)-3-bromobenzoates], were synthesized and were found to form nematic mesophase. The effects of the lateral substituent and the length of the central and terminal hydrocarbon chains on the mesomorphic properties of butane-1,4-diyl bis[4-(4-alkoxybenzoyloxy)-3- bromobenzoates] were studied. Structural factors responsible for mesogenic properties of these compounds were determined by conformation analysis.
