4- aminophenyl 4-nitrophenyl

The reactant corresponding to retrosynthetic path b in Scheme 2.2 can be obtained by Meerwein arylation of vinyl acetate with o-nitrophcnyldiazonium ions[9], Retrosynthetic path c involves oxidation of a 2-(o-nitrophenyl)ethanol. This transformation has also been realized for 2-(o-aminophenyl)ethanols. For the latter reaction the best catalyst is Ru(PPhj)2Cl2. The reaction proceeds with evolution of hydrogen and has been shown to be applicable to a variety of ring-substituted 2-(o-aminophenyl)ethanols[10]. 

Intermediates benzene to ethyl phenyl ketone to ethyl m nitrophenyl ketone to m aminophenyl ethyl ketone to ethyl m fluorophenyl ketone Reagents propanoyl chloride AICI3 HNO3 H2SO4 Fe HCl then HO NaN02 H2O HCl then HBF4 then heat... 

The rat LD qS are 13, 3.6 (oral) and 21, 6.8 (dermal) mg/kg. Parathion is resistant to aqueous hydrolysis, but is hydroly2ed by alkah to form the noninsecticidal diethjlphosphorothioic acid and -nitrophenol. The time required for 50% hydrolysis is 120 d ia a saturated aqueous solution, or 8 h ia a solution of lime water. At temperatures above 130°C, parathion slowly isomerizes to 0,%diethyl 0-(4-nitrophenyl) phosphorothioate [597-88-6] which is much less stable and less effective as an insecticide. Parathion is readily reduced, eg, by bacillus subtilis ia polluted water and ia the mammalian mmen to nontoxic 0,0-diethyl 0-(4-aminophenyl) phosphorothioate, and is oxidized with difficulty to the highly toxic paraoxon [511-45-5] diethyl 4-nitrophenyl phosphate d 1.268, soluble ia water to 2.4 mg/L), rat oral LD q 1.2 mg/kg. 

Acylation. Reaction conditions employed to acylate an aminophenol (using acetic anhydride in alkaU or pyridine, acetyl chloride and pyridine in toluene, or ketene in ethanol) usually lead to involvement of the amino function. If an excess of reagent is used, however, especially with 2-aminophenol, 0,A/-diacylated products are formed. Aminophenol carboxylates (0-acylated aminophenols) normally are prepared by the reduction of the corresponding nitrophenyl carboxylates, which is of particular importance with the 4-aminophenol derivatives. A migration of the acyl group from the O to the N position is known to occur for some 2- and 4-aminophenol acylated products. Whereas ethyl 4-aminophenyl carbonate is relatively stable in dilute acid, the 2-derivative has been shown to rearrange slowly to give ethyl 2-hydroxyphenyl carbamate [35580-89-3] (26). 

The dehydrogenative condensation of unsaturated ketones with methyl ketones was used for preparing various series of 2,4,6-tri-arylpyrylium salts not only by Dilthey, but also by Wizinger and co-workers (for combinations of phenyl, p-anisyl, and p-dimethyl-aminophenyl substituents), by Amoros-Marin and Carlin (combinations of phenyl and p-chlorophenyl), by Le Fevre and Le Fevre (for combinations of pbenyl and m- or p-nitrophenyl), and by others. ... 

Acyl-4-nitrophenyl 2-aminophenyl sulfides 1, obtained from 2-chloro-5-nitrophenyl ketones and 2-aminobcnzcncthiol, cyclizc, often spontaneously, to 2-nitrodibenzo[6,/][l,4]thiazepines 2.59... 

Many of the common reagents for introducing nitrophenyl chromophores into a molecule for DV-visible detection are also suitable for use with the electrochemical detector [554,555,637]. Some further exeuaples aure the formation of p-aminophenyl derivatives of carboxylic acids [637], N-(4-anilinophenyl) aaleimide derivatives of sulfadiydryl compounds [639], and... 

Aminophenyl disulfide Cystine, 2-Nitrophenyl disulfide Methyl disulfide, p-tolyl disulfide Benzyl disulfide Naphthothiophenes (NTH)... 

Both 2-azido [184] and 2-nitrophenyl isocyanides [185] are suitable synthons for the generation of the freely unstable 2-aminophenyl isocyanide and they have been used (Fig. 23) in the template-controlled preparation of NH,NH-stabilized benzim-idazolin-2-ylidene hgands. Both phenyl isocyanides coordinate readily to transition metal centers. The isocyanide ligand in complex 65 reacts with PPhs and the... 

The reduction of a dinitro ketone to an azo ketone is best achieved with glucose. 2,2 -Dinitrobenzophenone treated with glucose in methanolic sodium hydroxide at 60° afforded 82% of dibenzo[c,f [i 2]diazepin-l 1-one whereas lithium aluminum hydride yielded 24% of bis(o-nitrophenyl)methanol [575], Conversion of aromatic nitro ketones with a nitro group in the ring into amino ketones has been achieved by means of stannous chloride, which reduced 4-chloro-3-nitroacetophenone to 3-amino-4-chloroacetophenone in 91% yield [178]. A more dependable reagent for this purpose proved to be iron which, in acidic medium, reduced m-nitroacetophenone to m-aminoacetophenone in 80% yield and o-nitrobenzophenone to o-aminobenzophenone in 89% yield (stannous chloride was unsuccessful in the latter case) [903]. Iron has also been used for the reduction of o-nitrochalcone, 3-(o-nitrophenyl)-l-phenyl-2-propen-l-one, to 3-(o-aminophenyl)-l-phenyl-2-propen-l-one in 80% yield [555]. 

The application of diazo coupling is somewhat limited by the availability of the p-aminophenyl glycosides, particularly of those of the oligosaccharides. Their precursors, the p-nitrophenyl glycosides, are usually obtained by the condensation of a per-O-acetylated glycosyl halide with p-nitrophenol in ethanol (Michael reaction)19,20 or by the reaction of a per-O-acetylated sugar with p-nitrophenol in the presence of a Lewis acid catalyst (Helferich reaction).21 p-Nitrobenzyl 1-thioglycosides have also been prepared by the condensation of the... 

The surprising stability of triaryloxonium ions has been demonstrated by the fact that reduction of the tris(4-nitrophenyl)oxonium tetrafluoroborate 35 can be performed to give the tris(4-aminophenyl)oxonium salt 36 without cleavage of aryl oxygen bonds [Eq. (4.21)]. Diazotation of this amino derivative and reaction with iodide leads to the tris(/v/ra-iodophenyl)oxonium salt 37 in excellent yields.104... 

Hydrogenation of 9-benzyloxy-3,4-dihydro-l /T,8/T-pyrido[l, 2-aJpyr-azine-l,8-diones over Pd/C catalyst (10%) in MeOH gave 9-hydroxy derivatives (06WOP2006/066414). Transfer hydrogenation of 2-(4-nitrophenyl)perhydropyrido[l,2-fl]pyrazine over Pd/C catalyst with H2NNH2 H20 in EtOH yielded the respective 2-(4-aminophenyl) derivative (06JMC6351). 

Ethyl m-fluorophenyl m-Aminophenyl ethyl Ethyl m-nitrophenyl... 

Methyl 2-(p-nitrophenyl)acrylate (52 g) is hydrogenated in ethanol (500 ml) in the presence of 5% palladium-over-charcoal, while maintaining the temperature at +5°C. The theoretical amount of hydrogen is taken up within one hour. After separation of the catalyst and concentration to dryness, the resulting material gives methyl 2-(p-aminophenyl)proprionate which crystallizes MP = 40°-43°C. 

The fourth step was the conversation of 2-[2,6-dichloro-4-nitrophenyl) imino]imidazoline (150 g, 0.55 mol) in methanol (1,5 L) to 2-[(2,6-dichloro-4-aminophenyl)imino]imidazoline by hydrogen with 30 g Raney nickel catalyst at 23°C for 22 hours. After removing the catalyst hydrogen chloride gas was bubbled into solution until pH of the reaction mixture was 1.0. The solvent was rotary removed in vacuum and the residual solid was slurried with 2-propanol (1 L). The solvent was again removed by rotary evaporation, the cream solid was triturated with 2-propanol (600 ml). After aging for 1 hour, the solid was collected by filtration, washed with 2-propanol and t-butyl methyl ether, and dried for 15 hours at 6°C and t-butyl methyl ether, and dried for 15 hours at 60°C and 20 mm Hg. Yield of dihydrochloride 167 g... 

The solution of N-acetyl-N-(3-aminophenyl)-p-amino-isobutyric acid was filtered after standing overnight, mixed with an equal volume of acetic acid, and there after with a solution of 275.0 g iodine monochloride and 200.0 g sodium chloride in 1 L water. The mixture was kept at 50°C with stirring for 48 h. Light brown crystals of crude N-acetyl-N-(2,4,6-triiodo-3-aminophenyl)-p-amino-isobutyric acid precipitated, were filtered off, washed with water, and dried. They weighed 195.0 g (84.5% yield based on N-acetyl-N 3-nitrophenyl-p-amino-isobutyric acid). 

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