Search results
Results from the WOW.Com Content Network
Nitrobenzene is an aromatic nitro compound and the simplest of the nitrobenzenes, with the chemical formula C 6 H 5 NO 2. It is a water-insoluble pale yellow oil with an almond-like odor. It freezes to give greenish-yellow crystals. It is produced on a large scale from benzene as a precursor to aniline.
A modern synthesis entails reduction of nitrobenzene to phenylhydroxylamine (C 6 H 5 NHOH) which is then oxidized by sodium dichromate (Na 2 Cr 2 O 7). [5] Nitrosobenzene can also be prepared by oxidation of aniline using peroxymonosulfuric acid (Caro's acid) [6] or potassium peroxymonosulfate under biphasic conditions. [7]
Aniline is predominantly used for the preparation of methylenedianiline and related compounds by condensation with formaldehyde. The diamines are condensed with phosgene to give methylene diphenyl diisocyanate, a precursor to urethane polymers. [7] Most aniline is consumed in the production of methylenedianiline, a precursor to polyurethanes.
The reaction was first used by Antoine Béchamp to reduce nitronaphthalene and nitrobenzene to naphthylamine and aniline, respectively. [3] The Béchamp reduction is broadly applicable to aromatic nitro compounds. [4] [5] Aliphatic nitro compounds are however more difficult to reduce, often remaining as the hydroxylamine. Tertiary aliphatic ...
The nitration product produced on the largest scale, by far, is nitrobenzene. Many explosives are produced by nitration including trinitrophenol (picric acid), trinitrotoluene (TNT), and trinitroresorcinol (styphnic acid). [3] Another but more specialized method for making aryl–NO 2 group starts from halogenated phenols, is the Zinke nitration.
This compound can be prepared by the reduction of nitrobenzene with zinc in the presence of NH 4 Cl. [ 1 ] [ 2 ] Alternatively, it can be prepared by transfer hydrogenation of nitrobenzene using hydrazine as an H 2 source over a rhodium catalyst .
The Skraup synthesis is a chemical reaction used to synthesize quinolines.It is named after the Czech chemist Zdenko Hans Skraup (1850-1910). In the archetypal Skraup reaction, aniline is heated with sulfuric acid, glycerol, and an oxidizing agent such as nitrobenzene to yield quinoline.
Nitrobenzene can be obtained by treating benzenediazonium fluoroborate with sodium nitrite in presence of copper. Alternatively, the diazotisation of the aniline can be conducted in presence of cuprous oxide, which generates cuprous nitrite in situ: [C 6 H 5 N 2] + + CuNO 2 → C 6 H 5 NO 2 + N 2 + Cu +