O Bromophenol

Moat phenols are crystalline solids notable exceptions are m-cresol and o-bromophenol. The monohydric phenols generally have characteristic odours. The solubihty in water increases with the number of hydroxl groups in the molecule. 

Thus o-hydroxyphenyl-llthium cannot be obtained from o-bromophenol and lithium but, under proper conditions, o-bromophenol reacts with n-butyl-lithium to give a good yield of the lithium salt of o-hydroxyphenyl-hthium. An interesting application is to the preparation from m-bromochlorobenzene and M-butyl-lithlum of w-chlorobenzoic acid—an expensive chemical ... 

The flask is then heated in an oil bath maintained at a temperature of 190-210° and the mixture subjected to steam distillation. The sulfonate groups are hydrolyzed in this process and the bromophenol passes over as a heavy, colorless or pale yellow oil. In about one hour the distillate is clear. The product is extracted with ether, the ether is removed by distillation from the steam bath, and the residue is distilled at atmospheric pressure (Note 3). The fraction boiling at 194-200° represents practically pure o-bromophenol. The yield is 70-75 g. (40-44 per cent of the theoretical amount) (Note 4). t -Bromophenol is a colorless liquid with a very characteristic odor. It is rather unstable and decomposes on standing, becoming brown or red in color. 

The intramolecular mechanism of this reaction is proved by cross experiments for the metallation and 1,3-rearrangement reaction. In the same manner it is possible to yield the benzoxasiloles 11 (Eq.(4)). The first step in the reaction of chloromethylsilylethers of o-bromophenol 10 with sodium in boiling toluene is the metallation, followed by 1,3-rearrangement and intramolecular cyclization [8]. 

Analogous to the annulation of the Sonogashira adducts (see Section 6.4.), a spontaneous cyclization via the intramolecular alkoxylation of alkyne 117 (the coupling adduct of o-bromophenol and phenyl acetylene) took place under the reaction conditions to give 2-phenylbenzofuran 119 [93]. Benzofurylpalladium complex 118 was the putative intermediate during the cyclization. 

Bromopentane, 279 p-Bromophenacyl bromide, 960, 961 p-Bromophenacyl esters, 362 o-Bromophenol, 666, 679 p-Bromophenol, 666, 679 Bromophenol blue, 989, 990... 

Table III also presents our data for the extraction of Group 4 phenols from aqueous solutions. The o-bromophenol was added as an internal standard when some initial recovery problems were noted for the 2,6-di-terf-butyl-4-methylphenol results for its extraction are also reported here. The three phenols show good recoveries in the traps and overall good mass recoveries. One experiment was conducted under liquid C02 extraction conditions (temperature = 30 °C and pressure = 1500 lb/in.2) in an attempt to compare the relative efficiencies of the two states of CO2 for phenol extraction. Unfortunately, the phenols showed evidence of substantial breakthrough from the trapping system. The experiment does, however, demonstrate that liquid CO2 is also a good extractant for phenols present in water at parts-per-billion concentration levels.

The absorption curves for o-bromophenol and o-iodophenol are similar to those for o-chlorophenol, the shifted peaks lying at 6860 and 6800 cm-1, respectively. Guaiacol, o-methoxyphenol, shows a single peak at 6930 cm- 1, corresponding to the cis configuration... 

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