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 (JSmol)	Interactive image;
ECHA InfoCard	100.002.614
CompTox Dashboard (EPA)	DTXSID3025889 ;
	SMILES ONC1=CC=CC=C1;
Properties
Chemical formula	C6H7NO
Molar mass	109.1274 g/mol
Appearance	yellow needles
Melting point	80-81 °C
Related compounds
	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, is C₆H₅ONH₂.

Preparation and derivatives

This compound can be prepared by the reduction of C₆H₅NO₂ with zinc in the presence of NH₄Cl followed by crystallization as yellowish needles from salt-saturated water.^[1]^[2] Alternatively, it can be prepared by transfer hydrogenation of C₆H₅NO₂ using hydrazine as an H₂ source over a rhodium catalyst.^[3] The product can be purified from contaminating NaCl by extraction into benzene followed by precipitation with petroleum ether. C₆H₅NHOH 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

^ 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).
^ O. Kamm (1941). "Phenylhydroxylamine". Organic Syntheses; Collected Volumes, vol. 1, p. 445.
^ 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". Organic Syntheses{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 16, p. 16.
^ I. Brüning, R. Grashey, H. Hauck, R. Huisgen, H. Seidl (1973). "2,3,5-Triphenylisoxazolidine". Organic Syntheses{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 5, p. 1124.

[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". Organic Syntheses; Collected Volumes, 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". Organic Syntheses{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 16, p. 16.

[4] I. Brüning, R. Grashey, H. Hauck, R. Huisgen, H. Seidl (1973). "2,3,5-Triphenylisoxazolidine". Organic Syntheses{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 5, p. 1124.

[1]

[2]

[3]

[4]