Nitrosobenzene

Nitrosobenzene

Names
IUPAC name Nitrosobenzene
Identifiers
CAS Number	586-96-9 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:27986 N
ChEMBL	ChEMBL98797 Y
ChemSpider	10989 Y
ECHA InfoCard	100.008.721
KEGG	C06876 Y
PubChem	11473
RTECS number	DA6497525
InChI InChI=1S/C6H5NO/c8-7-6-4-2-1-3-5-6/h1-5H Y Key: NLRKCXQQSUWLCH-UHFFFAOYSA-N Y InChI=1/C6H5NO/c8-7-6-4-2-1-3-5-6/h1-5H Key: NLRKCXQQSUWLCH-UHFFFAOYAR
SMILES O=Nc1ccccc1
Properties
Chemical formula	C6H5NO
Molar mass	107.11 g·mol−1
Appearance	Colorless solid
Melting point	65 to 69 °C (149 to 156 °F; 338 to 342 K)
Boiling point	59 °C (138 °F; 332 K) (at 18 mmHg)
Solubility in water	Low
Solubility in other solvents	Sol. in organic solvents
Magnetic susceptibility (χ)	-59.1·10−6 cm3/mol
Structure
Molecular shape	N is sp2
Hazards
Main hazards	toxic
R-phrases	R20/21–R25
S-phrases	S26–S36/37–S45
Related compounds
Related compounds	Nitrobenzene Aniline
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Nitrosobenzene is the organic compound with the formula C₆H₅NO. This diamagnetic species exists in equilibrium with its dimer.

Nitrosobenzene was first prepared by Adolf von Baeyer by the reaction of diphenylmercury and nitrosyl bromide:

The modern synthesis entails reduction of nitrobenzene to phenylhydroxylamine (C₆H₅NHOH) which is then oxidized by sodium dichromate (Na₂Cr₂O₇).

Nitrosobenzene can also be prepared by oxidation of aniline using peroxymonosulfuric acid (Caro's acid). It is usually purified by steam distillation, where it comes over as a green liquid that solidifies to a colorless solid.

Nitrosobenzene undergoes Diels–Alder reactions with dienes. Condensation with anilines affords azobenzene derivatives in a reaction known as the Mills reaction. Reduction of nitrosobenzene produces aniline.

Most characteristically, nitrosobenzene condenses with active methylene groups, such as those of malonic esters and benzyl cyanide. For example, condensation with benzylcyanide (PhCH₂CN) gives the imine (PhC(CN)=NPh) in a reaction known as the Ehrlich-Sachs Reaction:

Sometimes condensation with active methylene compounds could give products of O-nitroso-aldol reaction: