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.
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.
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.
