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| Nitrosobenzene | |
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| IUPAC name | Nitrosobenzene |
| Other names | ? |
| Identifiers | |
| CAS number | [586-96-9] |
| RTECS number | DA6497525 |
| SMILES |
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| Properties | |
| Molar mass | 107.11 g/mol |
| Appearance | colourless solid |
| Density | ? g/cm3, ? |
| Melting point |
65-69 °C |
| Boiling point |
59 °C, 18 mm Hg |
| Solubility in water | low |
| Solubility in other solvents | sol. in organic solvents |
| Structure | |
| Molecular shape | N is sp2 |
| Hazards | |
| Main hazards | toxic |
| R-phrases | 20/21-25 |
| S-phrases | 26-36/37-45 |
| Related compounds | |
| Related compounds | Nitrobenzene Aniline |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references |
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Nitrosobenzene is the organic compound with the formula C6H5NO. The compound can be viewed as hybrid of singlet O2 and azobenzene. This diamagnetic species exists in equilibrium with its dimer.
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Preparation
C6H5NO was first prepared by Adolf von Baeyer by the reaction of diphenylmercury and nitrosylbromide:[1]
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- [C6H52Hg + BrNO → C6H5NO + C6H5HgBr
The modern synthesis entails reduction of nitrobenzene to phenylhydroxylamine, C6H5NHOH, which is then oxidized by Na2Cr2O7.[2] C6H5NO can also be prepared by oxidation of aniline using peroxymonosulfuric acid, Caro's acid.[3] It is usually purified by steam distillation, where it comes over as a green liquid that solidifes to a colorless solid.
Characteristic reactions
The monomer undergoes Diels-Alder reactions with dienes.[4] Most characteristically nitrosobenzene condenses with "active" methylene and amine groups, e.g. of malonic esters. Condensation with anilines affords azobenzene derivatives (Mills reaction)[5] and condensation with benzylcyanide PhCH2CN the imine PhC(CN)=NPh (The Ehrlich-Sachs Reaction).[6]
Reduction of PhNO produces C6H5NH2.
See also
References
- ^ Baeyer, A. "Nitrosobenzol und Nitrosonaphtalin" Chemische Berichte 1874, volume 7, pp.1638–1640.
- ^ G. H. Coleman, C. M. McCloskey, F. A. Stuart (1955). "Nitrosobenzene". Org. Synth.; Coll. Vol. 3: 668.
- ^ H. Caro, Z. angew. Chem., volume 11, p 845ff (1898).
- ^ H. Yamamoto, N. Momiyama "Rich Chemistry of Nitroso Compounds" Chemical Communications 2005, pp.3514–3525.
- ^ H. D. Anspon (1955). "p-Phenylazobenzoic Acid". Org. Synth.; Coll. Vol. 3: 711.
- ^ H. Feuer in S. Patai (ed.) "The Chemistry of the Nitro and Nitroso Groups Part 1," Wiley: New York. pp. 278-283
