Nitrophenols alkylated

Nitrophenols, alkylation, 148 o-Nitrophenol-p-sulfonic add, 107 p-Nitrophenyloxamic add, 93 o-NitrophenyBiydrazine, 97 p-NitrophenyDiydrazine, 95 Nitrophenylpyrazolones, 97 Nitrosobenzene, 78 p-Nitrosodiediylaniline, 309 p-Nitrosodimediylaniline, 308, 311 reduction, 78, 312 Nitroso- -naphthol, 80, 201 p-Nitrosophenol, 85 Nitrosylsulfuric add, 9, 247 o-Nitrotoluene, 53, 160 m-Nitrotoluene, 51 Nitrotoluenes, 3... 

This is the strategy of the manufacture of carbo-Jjran, though the mono alkylation of (28) is avoided by -sing available (29) and converting the NOg to OH by reduction and substitution. The acidic nitrophenol (30) rycllses on heating. 

See entry alkyl nitrates See other BENZYL compounds 2766. 3-Methyl-4-nitrophenol... 

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... 

Enantio- and diastereoselective syntheses of a variety of heterocycles were accomplished by combining the ruthenium-catalyzed Alder-ene reaction with a palladium-catalyzed asymmetric allylic alkylation (AAA) (Scheme 7). For the AAA, y>-nitrophenol was found to function as a suitable leaving group and yet was stable to the Alder-ene conditions. Extensive solvent studies were performed to determine the best conditions for the one-pot procedure. 

Of the substituted phenol ethers the amino-derivatives of anisole (anisidine) and phenetole (pkenetidine) may be mentioned. They are prepared from the nitrophenols by alkylation and subsequent reduction of the nitro-group. 

Many organic chemicals are analyzed by RPC. These include various arylhydroxylamines as the N-hydroxyurea derivative with methyl isocyanate (614) alkyl- and alkoxy-disubstituted azoxybenzenes (6t5), n-alkyl-4-nitrophenylcarbonate esters ranging in length from methyl to octyl (616), 4-nitrophenol in the presence of 4-nitrophenyl phosphate (617), ben-zilic acid, and benactyzine-HCI using ion-pair chromatography (618), as well as aniline and its various metabolites (619), stereoisomers of 4,4 -dihydroxyhydrobenzoin (620), and aldehydes and ketones as the 2,4-dinitrophenylhydrazones (621). The technique has also been used to analyze propellants and hydrazine and 1,1-dimethylhydrazine were quantitita-vely determined (622, 623). 

The second-resolution approach relied on enzymatic resolution of acetate esters 62 (Scheme 4.7) (Hayakawa et ah, 1991). The sequence opened with the alkylation of 2,3-difluoro-6-nitrophenol (59) with l-acetoxychloro-2-propane (60) to deliver ether 61. Reduction of the nitro group of 61 gave an intermediate anihne that cyclized to give racemic benzoxazine 62 in 62% yield. A variety of lipases were then examined for the resolution. The best results arose from use of LPL Amano 3, derived from P. aeruginosa, which gave a ratio of 73 23 in favor of the desired (—)-enantiomer. Benzoylation of the enantiomerically-enriched mixture followed by chromatography of the aryl amides delivered enantiomerically pure 63. 

Sulfur Bake. The yellow, orange, and brown sulfur dyes belong to this group. The dyes are usually made from aromatic amines, diamines, and their acyl and nuclear alkyl derivatives. These may be used in admixture with nitroanilines and nitrophenols or aminophenols to give the desired shade. The color formed is said to be the result of the formation of the thiazole chromophore, evident in dye structure (1). 

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... 

In the first step p-nitrophenol is alkylated on its phenolic oxygen with ethyl bromide. 

A similar effect of pH on dissolution rates of Mn(III/IV) oxides was observed by Stone (1987b) with substituted phenols. In this study, phenols with alkyl, alkoxy, or other electron, donating substituents were more slowly degraded. Stone (1987b) even found that p-nitrophenol, the most resistant phenol studied, reacted slowly with Mn(III/IV) oxides. 

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