Tribromo phenol

Reagent /PhOH 2,6-dibromo- phenol 2,4,6-tribromo- phenol 2-bromo- phenol 2,4-dibromo- phenol 4-bromo- phenol ... 

Fhenanthienequinone, 58,12, 16 1,10-Phenanthroline, 58, 43 Fhenethyl bromide, 56, 82 Phenol, thio-, 55,122 Phenol, 2,4,6-tribromo-, 55, 20 DL-Phenylalamne,A-(trif]uoroacetyl)-,... 

Perbenzoic acid, m-chloio- [Benzenecar-boperoxoic acid, 3-chloro-]-, SS, 88 PHASE TRANSFER ALKYLATION, 55, 91 PHASE TRANSFER CATALYSIS, 55, 96 Phenol, thio- [Benzenethiol], 55, 122 Phenol, 2,4,6-tribromo-, 55, 20 m-Phenylenediamine [ 1,3-Benzenediamine], p-bromination of, 55, 23 Phosphine, phenyl-, bis(3-dimethylamino-propyl)- [1-Propanamine, 3,3 -(phenyl-phosphinidene)bis(Af,Af-dimethyl)-),... 

Phenol, 4-cyano-Phenol, 3-nitro-Phenol, 2-methyl-Phenol, 3-chloro-Phenol, 4-bromo-Phenol, 2-methyl-4,6-dinitro-Phenol, 2,6-dibromo-4-cyano-(3,5-Dibromo-4-hydroxybenzonitrile) Phenol, 4-tert-butyl-Phenol, 2,4,6-tribromo-Phenol, 2-sec-butyl-4,6-dinitro-Phenol, 2-tert-butyl-4,6-dinitro-Phenol, pentachloro-... 

It is also to he noted that ortho and para substitution often occur together in the same molecule, so that the group R enters the para and also both the ortho positions thus both aniline and phenol on bromination readily give symmetric (2,4,6) tribromo-compounds (p. 165), while both toluene and phenol on nitration readily give the symmetric trinitro-derivatives (p. 170). 

RCH(OH)=CHCOR or -keto esters RCH(OH)=CHCOOR ) dissolve in dilute sodium hydroxide solution, i.e., contain an acidic group of sufficient strength to react with the alkah. Carboxyhc acids and sulphonic acids are soluble in dilute solutions of sodium bicarbonate some negatively-substituted phenols, for example, picric acid, 2 4 6-tribromo-phenol and 2 4-dinitrophenol, are strongly acidic and also dissolve in dilute sodium bicarbonate solution. 

For the organic contaminants, the required bromine product quality wilt also be site specific. If the catalytic oxidation unit is dedicated to a single bromination process, phase separation and drying may be the only purification required. Contaminants in the recovered bromine which are either the starting materials or products of the original bromination reaction should not present a problem if present in bromine recycled to the bromination reactor. In this case, the catalytic reactor would be operated to minimize the formation of undesirable brominated byproducts. For example, if phenol is present in the waste HBr from a tribromo-phenol manufacturing process, minor tribromophenol contamination of the bromine recycled to the reactor should not be a problem. Similarly, fluorobenzene in bromine recycled to a fluorobenzene bromination process should not present a problem. 

Phenols are transformed into aryl chlorides by PhPCl4779. Aromatic and aliphatic aldehydes give, in high yields, gem dibromides with combination of triphenylphosphite and bromine780. Brominative deoxygenation of ketones is achieved by 2,2,2-tribromo-l,2,3-benzodioxaphosphone781. Allylic alcohols are transformed into allylic iodides by reaction with P2I4782. 

Benzene does not react with bromine except with Lewis acid catalysis. Phenols react in a very different manner no Lewis acid is needed, the reaction occurs very rapidly, and the product contains three atoms of bromine in specific positions. All that needs to be done is to add bromine dropwise to a solution of phenol in ethanol. Initially, the yellow colour of the bromine disappears but, if, when the colour just remains, water is added, a white precipitate of 2,4,6-tribromo phenol is formed. 

The electron affinities of the anilines can be compared to those of the phenols and halobenzenes. The Ea of the trichloranilines should be less than that for the trichlorphenols or about 0.6 eV. The NIMS for the anilines are very similar to that of the phenols, except that less loss of HX occurs. The Ea for the tribromo-anilines should be about 0.75 eV, while that for pentachloroaniline and pentabromo-aniline should be 1.1 eV and 1.4 eV. The CURES-EC values are 1.2 eV and 1.45 eV. 

We close this discussion with two tribrominated phenols, the 2,4,6-tribromo derivatives of phenol and 3-methylphenol. We might expect equation 15 for estimating the enthalpy of formation of the deoxygenated 1,3,5-tribromobenzene to be approximately thermoneutral for all phases, assuming no interactions among substituents. 

On p. 479 of the textbook we explain the formation of 2,4,6-tribromophenol by bromination of phenol in water. It looks as though we can go no further as all the ortho and para positions are brominated. But we can if we treat the tribromo-compound with bromine in an organic solvent. Account for the formation of the tetrabromo-compound. 

We have seen above (p. 301) how three bi- and tri-substituted derivatives are derivable from l nzene. Phenol is a unisubstituted derivative of the same substance and hence still contains five H atoms which may be replaced by other elements or radicals. So long as but one otlier univalent atom or radical is introduced, the number of possible derivatives remains the same as if but one kind of atom or radical were introduced, as the reversal of the order Cl Br or Br Cl cannot influence the nature of the compound. Kut when the number of substituted atoms, differing in kind, is increased beyond two, or the valence of one or more of them exceeds one, the number of possible isomeres is progressively increased. Thus, while there are but three tribromo-beuzenes ... 

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