Search results
Results from the WOW.Com Content Network
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.
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.
Unlike the other isomers of nitrochlorobenzene, the meta isomer is not activated to nucleophilic substitution at the chlorine center. [1] However, 3-nitrochlorobenzene has other interesting reactivity. 3-Nitrochlorobenzene can be reduced to 3- chloroaniline with Fe/HCl mixture, the Bechamp reduction .
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.
By virtue of the two nitro substituents, the chloride in DNCB is particularly susceptible to nucleophilic substitution, at least relative to simple chlorobenzene. In this way, the compound is a precursor to many other compounds. [4] [5] [6] In one example, DNCB is as a substrate in Glutathione S-Transferase, relevant to activity assays. [7]
It contains a nitro group meta-substituted to the aldehyde. 3-Nitrobenzaldehyde is the primary product obtained via the mono-nitration of benzaldehyde with nitric acid. [3] C 6 H 5 CHO + HNO 3 → O 2 NC 6 H 4 CHO + H 2 O. Product distribution is about 19% for the ortho-, 72% for the meta- and 9% for the para isomers.
Commonly, 2-nitrochlorobenzene is treated with ammonia to generate 2-nitroaniline, whose nitro group is then reduced: [4] ClC 6 H 4 NO 2 + 2 NH 3 → H 2 NC 6 H 4 NO 2 + NH 4 Cl H 2 NC 6 H 4 NO 2 + 3 H 2 → H 2 NC 6 H 4 NH 2 + 2 H 2 O
m-Xylene (meta-xylene) is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes . The m- stands for meta- , indicating that the two methyl groups in m -xylene occupy positions 1 and 3 on a benzene ring.