NitrobenzeneNitrobenzene

Other names[hide]NitrobenzolOil of mirbane

Identifiers

CAS number98-95-3

PubChem7416

ChemSpider7138

UNIIE57JCN6SSY

KEGGC06813

ChEBICHEBI:27798

ChEMBLCHEMBL15750

RTECS numberDA6475000

Jmol-3D imagesImage 1

SMILES[show]

InChI[show]

Properties

Molecular formulaC6H5NO2

Molar mass123.06 g/mol

Appearanceyellowish liquid

Density1.199 g/cm3

Melting point5.7 C

Boiling point210.9 C

Solubilityinwater0.19 g/100 ml at 20 C

Hazards

EU classificationToxic (T)Carc. Cat. 3Repr. Cat. 3Dangerous for the environment (N)Flammable(F)

R-phrasesR10,R23/24/25,R40,R48/23/24,R51/53,R62

S-phrases(S1/2),S28,S36/37,S45,S61

NFPA 704321

Flash point88 C

Autoignitiontemperature525 C

Related compounds

Related compoundsAnilineBenzenediazonium chlorideNitrosobenzene

(verify)(what is:/?)Except where noted otherwise, data are given for materials in theirstandard state (at 25C, 100kPa)

Infobox references

Nitrobenzeneis anorganic compoundwith thechemical formulaC6H5NO2. It is a water-insoluble pale yellow oil with analmond-like odor. It freezes to give greenish-yellow crystals. It is produced on a large scale frombenzeneas a precursor toaniline. In the laboratory, it is occasionally used as asolvent, especially forelectrophilicreagents.Contents[hide] 1Production 1.1Mechanism of nitration 2Uses 2.1Specialized applications 2.2Organic reactions 3Safety 4References 5External links

Production[edit]Nitrobenzene is prepared bynitrationof benzene with a mixture of concentratedsulfuric acid,water, andnitric acid. This mixture is sometimes called "mixed acid." The production of nitrobenzene is one of the most dangerous processes conducted in the chemical industry because of the exothermicity of the reaction (H= 117 kJ/mol).[1]

World capacity for nitrobenzene in 1985 was about 1.7106tonnes.[1]Mechanism of nitration[edit]Main article:nitrationThe reaction pathway entails formation of an adduct between theLewis acidicnitroniumion (NO2+) and benzene. The nitronium ion is generated in situ by the reaction of nitric acid and an acidic dehydration agent, typically sulfuric acid:HNO3+ H+NO2++ H2OUses[edit]Approximately 95% of nitrobenzene is consumed in the production ofaniline,[1]which is a precursor torubberchemicals,pesticides,dyes,explosives, andpharmaceuticals.Specialized applications[edit]Nitrobenzene is also used in shoe and floor polishes, leather dressings, paintsolvents, and other materials to mask unpleasant odors. Redistilled, as oil of mirbane, nitrobenzene has been used as an inexpensive perfume forsoaps. A significant merchant market for nitrobenzene is its use in the production of theanalgesicparacetamol(also known as acetaminophen) (Mannsville 1991).[2]Nitrobenzene is also used inKerr cells, as it has an unusually largeKerr constant.Organic reactions[edit]Aside from its conversion to aniline, nitrobenzene is readily converted to related derivatives such asazobenzene,[3]nitrosobenzene,[4]andphenylhydroxylamine.[5]The nitro- group is deactivating, thus substitution tends to occur at themeta-position.Safety[edit]Nitrobenzene is highly toxic (Threshold Limit Value5mg/m3) and readily absorbed through the skin.Prolonged exposure may cause serious damage to the centralnervous system, impair vision, cause liver or kidney damage, anemia and lung irritation. Inhalation of vapors may induce headache, nausea, fatigue, dizziness,cyanosis, weakness in the arms and legs, and in rare cases may be fatal. The oil is readily absorbed through the skin and may increase heart rate, cause convulsions or rarely death. Ingestion may similarly cause headaches, dizziness, nausea, vomiting and gastrointestinal irritation, loss of sensation/use in limbs and also causes internal bleeding.[6]Nitrobenzene is considered a likely human carcinogen by the United States Environmental Protection Agency,[7]and is classified by theIARCas aGroup 2B carcinogenwhich is "possibly carcinogenic to humans".[8]It has been shown to cause liver, kidney, and thyroid adenomas and carcinomas in rats.[9]