5- Bromo-2-nitrophenol

Methylphenol in ethanolic solution treated with ferric nitrate nonahydrate (1 equiv.) and heated briefly for 30 sec. afforded an 83% yield of 4-methyl-2-nitrophenol. Under similar conditions 4-chlorophenol gave 4-chloro-2-nitrophenol (88%), 4-bromophenol gave 4-bromo-2-nitrophenol (64%) and 2-chlorophenol, a mixture of 2-chloro-4-nitrophenol (56%) and 2-chk>ro-6-nitrophenol (35%). Aluminium, chromium and copper(ll) nitrates were also used (ref.63). 

N)4C6(0H)Cl, colorl crysts from chlf or C tetrachloride, mp 174°. Can be prepd by the nitration of 5-chloro-3-nitrophenol with mixed nitric-sulfuric acids. It is an expl 5-Bromo-2,3,4,6-Tetranitrophenol. (02N)4C6(0H)Br, colorl crysts from chlf or C tetrachloride, mp 157°. Can be prepd by the nitration of 5-bromo-3-nitrophenol with mixed nitric-sulfuric acids. It is an expl Ref Bell 6, 293... 

Other electrophilic substitution reactions on aromatic and heteroaromatic systems are summarized in Scheme 6.143. Friedel-Crafts alkylation of N,N-dimethyl-aniline with squaric acid dichloride was accomplished by heating the two components in dichloromethane at 120 °C in the absence of a Lewis acid catalyst to provide a 23% yield of the 2-aryl-l-chlorocydobut-l-ene-3,4-dione product (Scheme 6.143 a) [281]. Hydrolysis of the monochloride provided a 2-aryl-l-hydroxycyclobut-l-ene-3,4-dione, an inhibitor of protein tyrosine phosphatases [281], Formylation of 4-chloro-3-nitrophenol with hexamethylenetetramine and trifluoroacetic acid (TFA) at 115 °C for 5 h furnished the corresponding benzaldehyde in 43% yield, which was further manipulated into a benzofuran derivative (Scheme 6.143b) [282]. 4-Chloro-5-bromo-pyrazolopyrimidine is an important intermediate in the synthesis of pyrazolopyrimi-dine derivatives showing activity against multiple kinase subfamilies (see also Scheme 6.20) and can be rapidly prepared from 4-chloropyrazolopyrimidine and N-bromosuccinimide (NBS) by microwave irradiation in acetonitrile (Scheme... 

Photolytic. A carbon dioxide yield of 19.7% was achieved when bromobenzene adsorbed on silica gel was irradiated with light (X >290 nm) for 17 h (Freitag et al., 1985). Irradiation of bromobenzene in air containing nitrogen oxides gave phenol, 4-nitrophenol, 2,4-dinitrophenol, 4-bromophenol, 3-bromonitrobenzene, 3-bromo-2-nitrophenol, 3-bromo-4-nitrophenol, 3-bromo-6-... 

Bromo-2-nitrophenol, see Bromobenzene 3-Bromo-4-nitrophenol, see Bromobenzene... 

Nitro alcohols were reduced to amino alcohols by catalytic hydrogenation over platinum [632] and with iron [JJ9], and nitrosophenols [255] and nitro-phenols [256] to aminophenols with sodium hydrosulfite, sodium sulfide [238] or tin [176]. Bromine atoms in 2,6-di-bromo-4-nitrophenol were not affected [176]. 

The second synthesis [6], based on radical chemistry to achieve the crucial Caryi-Cgryi bond, required as the starting material the 2-bromobenzyl-2 -aminophenyl ether (11) (Scheme 2). It was secured by alkylation of o-nitrophenol with 2-bromo-4,5-methylenedioxybenzyl chloride, followed by catalytic reduction of the resulting nitropheny ether. 11 when subjected to the action of tri-n-butyltinhydride in the presence of 2,2 -azobisisobutyronitrile furnished a... 

As previously described for aromatic carboxylic acids, measurements of the line-widths of the CH3 resonance in methanol give the rate of exchange of hydroxylic protons on methanol, and measurements of the line-widths of the OH resonance give the rate of exchange of protons on phenol. Values of ft, k2 and k3 have been determined for p-bromo-phenol and p-nitrophenol [67], and are tabulated in Table 11. 

C6H4BrCIO 3-bromo-5-chlorophenol 56962-04-0 25.00 1.7076 2 6519 C6H4FN03 4-fluoro-2-nitrophenol 394-33-2 25.00 1.4306 2... 

C7H7Br02 5-bromo-2-hydroxybenzenemethanol 2316-64-5 25.00 1.5519 2 10653 C7H7N03 2-methyt-6-nitrophenol 13073-29-5 28.40 1.2744 2... 

This is prepared by nitration in the usual manner, and crystallises from 50 per cent, acetic acid in plates, transformed by alkali into 8-bromo-6-nitrophenol. 

The sodium salt of o-nitrophenol is shaken with the calculated amount of mercuric acetate in aqueous solution, when the anhydride separates out as a yellow precipitate. When treated with bromine or iodine in potassium iodide, bromo-2-nitrophenol and iodO 2-nitrophenol result. 

Galactosidase. (EC 3.2.1.23) is an enzyme found in many bacterial and eukaryotic cell types that converts o-nitrophenyl P-D-galactoside to o-nitrophenol and D-galactose. It will also convert 5-bromo-4-chloro-3-indoyl... 

Bromo-4-methyl-6-nitrophenol (2-Bromo-6-nitro-p-cresol) 69, yel 128 IIO-II ... 

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