Phenylhydroxylamine

Phenylhydroxylamine

Names
IUPAC name N-phenylhydroxylamine
Other names beta-henylhydroxylamine; N-hydroxyaniline; phenylhydroxylamine; N-hydroxybenzeneamine; hydroxylaminobenzene
Identifiers
CAS Number	100-65-2
3D model (Jmol)	Interactive image
ChEBI	CHEBI:28902
ChemSpider	7237
ECHA InfoCard	100.002.614
EC Number	209-711-2
KEGG	C02720
PubChem	7518
UNII	282MU82Z9A
InChI InChI=1S/C6H7NO/c8-7-6-4-2-1-3-5-6/h1-5,7-8H Key: CKRZKMFTZCFYGB-UHFFFAOYSA-N InChI=1/C6H7NO/c8-7-6-4-2-1-3-5-6/h1-5,7-8H Key: CKRZKMFTZCFYGB-UHFFFAOYAK
SMILES ONC1=CC=CC=C1
Properties
Chemical formula	C6H7NO
Molar mass	109.1274 g/mol
Appearance	yellow needles
Melting point	80 to 81 °C (176 to 178 °F; 353 to 354 K)
Related compounds
Related compounds	hydroxylamine, nitrosobenzene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
verify (what is  ?)
Infobox references

Phenylhydroxylamine is the organic compound with the formula C₆H₅NHOH. It is an intermediate in the redox-related pair C₆H₅NH₂ and C₆H₅NO. Phenylhydroxylamine should not be confused with its isomer α-phenylhydroxylamine or O-phenylhydroxylamine.

Preparation

This compound can be prepared by the reduction of nitrobenzene with zinc in the presence of NH₄Cl followed by crystallization as yellowish needles from salt-saturated water.^[1][2] The product can be purified from contaminating NaCl by extraction into benzene followed by precipitation with petroleum ether.

Alternatively, it can be prepared by transfer hydrogenation of nitrobenzene using hydrazine as an H₂ source over a rhodium catalyst.^[3]

Reactions

Phenylhydroxylamine is unstable to heating, and in the presence of strong acids easily rearranges to 4-aminophenol. Oxidation of phenylhydroxylamine with dichromate is a useful method of preparation of nitrosobenzene.

The compound condenses with benzaldehyde to form diphenylnitrone, a well-known 1,3-dipole:^[4]

C₆H₅NHOH + C₆H₅CHO → C₆H₅N(O)=CHC₆H₅ + H₂O

References

1. E. Bamberger “Ueber das Phenylhydroxylamin” Chemische Berichte, volume 27 1548-1557 (1894). E. Bamberger, "Ueber die Reduction der Nitroverbindungen" Chemische Berichte, volume 27 1347-1350 (1894) (first report).
2. O. Kamm (1941). "Phenylhydroxylamine". Org. Synth.; Coll. Vol., 1, p. 445
3. P. W. Oxley, B. M. Adger, M. J. Sasse, and M. A. Forth (1993). "N-Acetyl-N-Phenylhydroxylamine via Catalytic Transfer Hydrogenation of Nitrobenzene using Hydrazine and Rhodium on Carbon". Org. Synth.; Coll. Vol., 16, p. 16
4. I. Brüning, R. Grashey, H. Hauck, R. Huisgen, H. Seidl (1973). "2,3,5-Triphenylisoxazolidine". Org. Synth.; Coll. Vol., 5, p. 1124