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Nitrochlorobenzene is typically synthesized by nitration of chlorobenzene in the presence of sulfuric acid: C 6 H 5 Cl + HNO 3 → O 2 NC 6 H 4 Cl + H 2 O. This reaction affords a mixture of isomers. Using an acid ratio of 30/56/14, the product mix is typically 34-36% 2-nitrochlorobenzene and 63-65% 4-nitrochlorobenzene, with only about 1% 3 ...
The U.S. National Institute for Occupational Safety and Health considers 4-nitrochlorobenzene as a potential occupational carcinogen. [7] The Occupational Safety and Health Administration set a permissible exposure limit of 1 mg/m 3 The American Conference of Governmental Industrial Hygienists recommends an airborne exposure limit of 0.64 mg/m 3 over a time-weighted average of eight hours.
The phrase ipso nitration was first used by Perrin and Skinner in 1971, in an investigation into chloroanisole nitration. [18] In one protocol, 4-chloro- n -butylbenzene is reacted with sodium nitrite in t -butanol in the presence of 0.5 mol% Pd 2 (dba) 3 , a biarylphosphine ligand and a phase-transfer catalyst to provide 4-nitro- n -butylbenzene.
Nitrochlorobenzene is typically synthesized by nitration of chlorobenzene in the presence of sulfuric acid: . C 6 H 5 Cl + HNO 3 → O 2 NC 6 H 4 Cl + H 2 O. This reaction affords a mixture of isomers.
A variation is formation of a dimethylaminoarene with palladium on carbon and formaldehyde: [21] Nitro compound hydrogenation. The α-carbon of nitroalkanes is somewhat acidic. The pK a values of nitromethane and 2-nitropropane are respectively 17.2 and 16.9 in dimethyl sulfoxide (DMSO) solution, suggesting an aqueous pK a of around 11. [22]
Chlorobenzene (abbreviated PhCl) is an aryl chloride and the simplest of the chlorobenzenes, consisting of a benzene ring substituted with one chlorine atom. Its chemical formula is C 6 H 5 Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals.
The nitration of 1,2-dichlorobenzene mainly produces 1,2-dichloro-4-nitrobenzene, together with smaller amounts of the 3-nitro isomer. It can also be prepared by chlorination of 1-chloro-4-nitrobenzene. [1] One of the chlorides is reactive toward nucleophiles.
The radical mechanism of the Sandmeyer reaction is supported by the detection of biaryl byproducts. [8] The substitution of the aromatic diazo group with a halogen or pseudohalogen is initiated by a one-electron transfer mechanism catalyzed by copper(I) to form an aryl radical with loss of nitrogen gas.