Nitrophenols, synthesis

Nitrophenols, irradiation of 1073 5-Nitrophenols, synthesis of 639 2-Nitroresordnol, IR LD spectrum of 384, 385 5-Nitrosalicylaldehyde, NMR spectra of 336 Nitrosation 606... 

Uses. (9-Nitrochlorobenzene is used in the synthesis of azo dye intermediates such as o-chloroaniline (Fast YeUow G Base), i9-nitroani1ine (Fast Orange GR Base), o-anisidine (Fast Red BB Base), o-phenetidine, and (9-aminophenol (see Azo dyes). It also is used in corrosion inhibitors, pigments, and agriculture chemicals. -Nitrochlorobenzene is used principally in the production of intermediates for azo and sulfur dyes. Other uses include pharmaceuticals (qv), photochemicals, mbber chemicals (qv), and insecticides (see Insectcontroltechnology). Typical intermediates manufactured from the para isomer are -lutioaruline (Fast Red GC Base), anisidine, -aminophenol, -nitrophenol, -phenylenediamine, 2-chloro-/)-anisidine (Fast Red R Base), 2,4-dinitrochlorobenzene, and l,2-dichloro-4-nitrobenzene. 

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... 

Synthesis of Immunogen (Hapten) The barbiturate, 5-ally 1-5-(1-carboxyisopropyl) barbituric acid (I) is first converted to 5-allyl-5-(1 -p-n i trophenyloxycarbonylisopropyl) barbituric acid (II) by the interaction of the base with /7-nitrophenol in N, N-dimethylformamide (DMF) as shown below ... 

Li, H., et al., Palladium nanoparticles decorated carbon nanotubes facile synthesis and their applications as highly efficient catalysts for the reduction of4-nitrophenol. Green Chemistry, 2012.14(3) p. 586-591. 

Lin and Zhang reported the synthesis of l-hydroxy-3-methylcarbazole (23) starting from the nitro derivative 625 (578). This synthesis uses a Buchwald-Hartwig amination for the synthesis of the diphenylamine 628. After protection of the hydroxy group in the nitrophenol 625 as a benzyl ether, the nitro group was reduced to the corresponding amino derivative 627. Amination of 627 with iodobenzene under Buchwald-Hartwig conditions afforded the diarylamine 628. Palladium(ll)-mediated cyclization of 628 led to the carbazole derivative 629, albeit in low... 

Menendez et al. reported the synthesis of murrayafoline A (7) by palladium(II)-mediated oxidative double C-H activation of a diarylamine assisted by microwave irradiation (585). The aniline derivative 598 was obtained by O-methylation of 5-methyl-2-nitrophenol (625) followed by catalytic hydrogenation. The required diarylamine 654 was obtained by N-arylation of the aniline derivative 598 with phenyllead triacetate (653) in the presence of copper(II) acetate. Under microwave-assisted conditions, in the presence of more than the stoichiometric amount of palladium(II) acetate and a trace of dimethylformamide, the diarylamine 654 was cyclodehydrogenated to murrayafoline A (7) (585) (Scheme 5.47). 

Crich and Rumthao reported a new synthesis of carbazomycin B using a benzeneselenol-catalyzed, stannane-mediated addition of an aryl radical to the functionalized iodocarbamate 835, followed by cyclization and dehydrogenative aromatization (622). The iodocarbamate 835 required for the key radical reaction was obtained from the nitrophenol 784 (609) (see Scheme 5.85). lodination of 784, followed by acetylation, afforded 3,4-dimethyl-6-iodo-2-methoxy-5-nitrophenyl acetate 834. Reduction of 834 with iron and ferric chloride in acetic acid, followed by reaction with methyl chloroformate, led to the iodocarbamate 835. Reaction of 835 and diphenyl diselenide in refluxing benzene with tributyltin hydride and azobisisobutyronitrile (AIBN) gave the adduct 836 in 40% yield, along with 8% of the recovered substrate and 12% of the deiodinated carbamate 837. Treatment of 836 with phenylselenenyl bromide in dichloromethane afforded the phenylselenenyltetrahydrocarbazole 838. Oxidative... 

The determination of the enzyme activity as a function of the composition of the reaction medium is very important in order to find the optimal reaction conditions of an enzyme catalysed synthesis. In case of lipases, the hydrolysis of p-nitrophenyl esters in w/o-microemulsions is often used as a model reaction [19, 20]. The auto-hydrolysis of these esters in w/o-microemulsions is negligible. Because of the microstructure of the reaction media itself and the changing solvent properties of the water within the reverse micelles, the absorbance maximum of the p-nitrophenol varies in the microemulsion from that in bulk water, a fact that has to be considered [82]. Because of this, the water- and surfactant concentrations of the applied micro emulsions have to be well adjusted. 

Induction of DNA single-strand breakage in rat liver after in-vivo exposure to N-nitrosodiethanolamine was demonstrated in three studies and dose-dependent effects were shown. In one of these studies, the DNA strand-breaking potential of 7V-nitroso-diethanolamine was found to be abolished by inhibition of sulfotransferase by 2,6-dichloro-4-nitrophenol. Unscheduled DNA synthesis was not detected in rats or mice in an in-vivo/in-vitro hepatocyte DNA repair assay after treatment with 7V-nitrosodi-ethanolamine. A single study in mice exposed in vivo to 7V-nitrosodiethanolamine did not find any significant induction of structural or numerical chromosomal aberrations or micronuclei in bone-marrow cells. 

Kraft, D., Cacciapaglia, R., Bohmer, V.. El-Eadl, A.A., Harkema, S., Mandolini. L., Reinhoudt, D.N., Verboom, W. and Vogt, W. (1992) New crown ether-like macrocycles containing a nitrophenol unit. Synthesis and metal ion effects on the reactivity of their acetates in transcylation reactions. J. Org. Chem., 57, 826. 

Benzimidazoles and their derivatives possess varied pharmacological activities59 60 and have therefore been targets of intense synthetic efforts using both solution- and solid-phase methods. In one of the pioneering studies on the assembly of benzofused heterocycles via SvAr reactions of o-fluoro-ni-troarenes, Phillips and Wei reported a solid-phase synthesis of benzimidazoles from 3-fluoro-4-nitrophenol, amines, and ethyl benzimidates (Scheme 13).61... 

W. M. Mullett, P. Martin, and J. Pawliszyn, In-Tube Molecularly Imprinted Polymer Solid-Phase Microextraction for the Selective Determination of Propranolol, Anal. Chem. 2001, 73, 2383 N. Masque, R. M. Marce, F. Borrull, P. A. G. Cormack, and D. C. Sherrington, Synthesis and Evaluation of a Molecularly Imprinted Polymer for Solid-Phase Extraction of 4-Nitrophenol from Environmental Water, Anal. Chem. 2000, 72, 4122. 

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... 

MASQUE N, MARCE R M, BORULL F, CORMACK PAG and SHERRINGTON D C (2000), Synthesis and evaluation of a molecularly imprinted polymer for selective on-line solid-phase extraction of 4-nitrophenol from environmental water , Anal Chem, 72, 4122-4126. 

In the synthesis of the symmetrical 1 2 cobalt azomethine complex 19 [41043-60-1] [31], a mixture of 2-amino-6-nitrophenol-4-sulfonic acid and salicylaldehyde is heated to boiling in sodium acetate solution. The suspension is cooled and mixed first with CoCl2-6H20 and then with 30% H202. The resulting solution is salted out with NaCl and KC1. The dye yields exceptionally lightfast yellow colors on wool and polyamides. 

Nitro alcohols are nonaromatic compounds containing both -OH and -N02 groups. A typical example of such a compound is 2-nitro-l-butanol, shown below. These compounds are used in chemical synthesis to introduce nitro functional groups or (after reduction) amino groups onto molecules. They tend to have low volatilities and moderate toxicities. The aromatic nitrophenol, / -nitrophenol, is an industrially important compound with toxicological properties resembling those of phenol and nitrobenzene. 

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