Phenyl hydroxyl amine

Also related to these and best considered at this time we have  

The first of these compounds, nitroso benzene, has been fully considered as the nitrous acid derivative of benzene (p. 538). 

When nitro benzene is reduced in neutral solutions by means of zinc in hot water or hot alcohol or when an ether solution of it is reduced by means of aluminium amalgam and water or when it is reduced electro-lytically, the product is phenyl hydroxyl amine. 

Phenyl hydroxyl amine is the phenyl derivative of hydroxyl amine, NH2—OH, which was considered in Part I (p. 63). Like the parent 

Oxidation Products.—With different oxidizing agents it yields various products. Its water solution oxidizes easily in the air and yields azoxy benzene. 

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Figure 11.14 Formation of instable intermediates during the catalytic hydrogenation of nitro-aromatic compounds. The decomposition of phenyl hydroxyl amine (I) is shown in the thermogram at 70% of hydrogen uptake. The decomposition of the nitro aromatic compound (D) decreases as the hydrogenation progresses.

Nitroso-benzene. —Intermediate between nitro benzene and phenyl hydroxyl amine is the nitrous acid derivative or nitroso benzene. This compound can not be formed by reduction of the nitro benzene, but is obtained by oxidizing phenyl hydroxylamine. 

Nitroso Benzene.—The nitroso or nitrous acid derivatives are exactly analogous to the nitro or nitric acid derivatives. As the nitro radical is (AO2), so the nitroso radical is NO) and whenever this radical is present, as we found in the nitroso-amines (p. 61), and as we shall find in some more complex compounds of the dye class, it means nitroso derivative. The simplest representative, viz., nitroso benzene, CeHs—NO, differs from nitro benzene in that it is not formed by the direct action of the acid on the hydrocarbon nor, as shown above, is it able to be isolated as a reduction product of nitro benzene. It is prepared, however, by the oxidation of phenyl hydroxyl amine, either by means of ferric chloride, FeCU, or of chromic acid, CrOa. 

Molecular Rearrangement to para-Amino Phenol.— Phenyl hydroxyl amine undergoes an important molecular rearrangement. When boiled with mineral acids it is converted into para-amino phenol. 

The rearrangement occurs also when nitro benzene is electrolytically reduced by immersing the cathode in nitro benzene and sulphuric acid and the anode in sulphuric acid. Phenyl hydroxyl amine is first produced and by the above rearrangement is converted into para amino phenol. This rearrangement is analogous to the one occurring when phenyl methyl nitrosamine goes over to para-nitroso methyl aniline (P- S59)-... 

As has just been stated, it is also formed by the oxidation of phenyl hydroxyl amine even in the air. In this case there is a loss of four hydrogens and one oxygen from two molecules. 

Rearrangement.—Like nitroso methyl aniline and phenyl hydroxyl amine it undergoes molecular rearrangement as above. 

N-Phenylhydroxylamine, mp 83.5-85°C, can be isolated at this stage in 75-85% yields if desired, but it should be borne in mind that N-phenyl hydroxyl amine is not very stable. The isolation can be carried out by adding an equal volume of methylene chloride to the tetrahydrofuran solution which is then dried over magnesium sulfate and concentrated to low volume under reduced pressure. Addition of a little petroleum ether precipitates N-phenylhydroxyl amine which is then filtered and washed with petroleum ether. 

No vigorous, exothermic reaction is seen during the addition of acetyl chloride, but the additon should be slow because of the heterogeneous nature of the reaction and the need to destroy efficiently hydrogen chloride as it is formed. The product, like N-phenyl hydroxyl amine. Is sensitive to... 

X R Mol N2H4 Reaktions-temp. f°C] Daucr [Stdn.]. . phenyl)-hydroxyl-amin Ausbeute [% 4. Th.] F rci... 

Aniline was found by GLC to be the only reaction product. The well-known possible intermediates nitrosobenzene, N-phenyl hydroxyl-amine, azobenzene, and hydrazobenzene could all be hydrogenated by the same catalyst combination to aniline. Comparing the rates of hydrogenations (Table I), the only conclusion one can reach about the mechanism of nitrobenzene hydrogenation is that nitrosobenzene and N-phenyl hydroxylamine (and thus probably also azobenzene and hydrazobenzene) are not intermediates of the reaction. 

B. B-Aoetyl-9-phenylhydpoxylamine, To the N-phenyl hydroxyl amine solution in a 1000-mL, three-necked, round-bottomed flask fitted with a mechanical stirrer and thermometer is added a slurry of sodium bicarbonate (42... 

Noyes and Clement, on the reduction of nitrobenzene in a concentrated sulphuric acid solution, obtained p-amido-phenol-sulphonic acid. Gatter-mann, starting with a similar solution, by varying the conditions of the experiment obtained directly p-amido-phenol. He explains the reaction by assuming the intermediate formation of phenyl-hydroxyl-amine, which on further reduction changes by molecular rearrangement into the final product. By similar treatment were formed ... 

Extractant C-j HgOgN N-Furoyl-N-phenyl hydroxyl amine, HA Distribution constants ... 

N Phenyl-N- [4 nitro80-phenyl]-hydroxyl amin 15,11, II10. 

Indium(III) JV-Benzoyl-JV-phenyl hydroxyl-amine Pg 628 Iodide... 

I ron (III) AT-benzoy I-JV-phenyl hydroxyl-amine Pg 628 Iron (bipy)s BMP 140-143 Iron (CsHe) ... 

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