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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 reduction of nitrobenzene to aniline was also performed as part of reductions by Antoine Béchamp in 1854, using iron as the reductant (Bechamp reduction). These stoichiometric routes remain useful for specialty anilines. [17] Aniline can alternatively be prepared from ammonia and phenol derived from the cumene process. [7]
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 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]
Béchamp developed the Béchamp reduction, an inexpensive method to produce aniline dye, permitting William Henry Perkin to launch the synthetic-dye industry. Béchamp also synthesized the first organic arsenical drug, arsanilic acid, from which Paul Ehrlich later synthesized salvarsan, the first chemotherapeutic drug.
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 +
The reduction of nitroaromatics is conducted on an industrial scale. [1] Many methods exist, such as: Catalytic hydrogenation using: Raney nickel [2] or palladium-on-carbon, [3] [4] [5] platinum(IV) oxide, or Urushibara nickel.