2,6-Dibromo-4-nitrophenol

Dibromo-4-nitrophenol [99-28-5] M 280.9, m 143-144°. Crystd from aqueous EtOH. 

Dibromo-4-nitrophenol has been prepared by the nitration of 2,6-dibromophenol1 or of dibromophenol sulfonic acid,2 and by the action of nitric acid on 2,6-dibromo-4-nitroso-phenol3 or on 2,4,6-tribromophenol.4 It has been obtained from the corresponding ethyl ether 5 and by the action of bromine on />-nitrosophenol,6 4,6-dibromo-2-nitrophenol,7 5-nitro-2-hydroxy-benzoic acid,8 and 5-nitro-2-hydroxybenzenesulfonic acid.9 The dibromination of />-nitrophenol I0>13 has been carried out in sulfuric acid solution 11 and in the presence of aluminum chloride.12 The method described here is essentially that of M"hlau and Uhlmann.13... 

Generated in situ from sodium bromide and chlorine, the reagent is useful for bromination of phenols p-nitrophenol- 2,6-dibromo-4-nitrophenol (96% yield). ... 

PAMAM G1-G3 OH or ester Benzoic acid Salicylic acid Iodine 3-Amino-1,5-dibromophenol 2,6-Dibromo-4-nitrophenol Antibacterial Yes Yes No 273... 

Chlorine passed with vigorous stirring at 45-55° into an aq. soln. of p-nitro-phenol and NaBr until a persistent Br-color indicates completion of the reaction 2,6-dibromo-4-nitrophenol. Y 96%.— The reaction time has been shortened considerably by the use of bromine chloride instead of bromine in acetic acid. C. O. Obenland, J. Chem. Educ. 566 (1964). 

Selective Functional Group Conversion of Phenols or Aromatic Ethers. The selective conversion of para-oriented functional groups of substituted phenols and aromatic ethers to ni-tro groups has been accomplished using nitric acid. For example, 2,4,6-tribromophenol can be converted to 2,6-dibromo-4-nitrophenol upon reaction with 1 equiv of nitric acid in ether (eq 26). The selective conversion of tert-butyl groups into ni-tro groups has also been extensively developed and used in the preparation of aromatic substrates and in calixarene chemistry (eq 27). 3- ... 

Bromination of p-Nitrophenol in Aqueous Solution with Bromine Chloride To Give 2,6-Dibromo-4-nitrophenol... 

Bromine monochloride reacts with p-nitrophenol to give 2,6-dibromo-4-nitrophenol, indicating that the more electrophilic bromine group reacts preferentially. 

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