2,4-Dinitrochlorobenzene
2,4-Dinitrochlorobenzene is an organic compound with the chemical formula 2C6H3Cl. It is a yellow solid that is soluble in organic solvents. It is an intermediate for the industrial production of other compounds.
Preparation and reactions
DNCB is produced commercially by the nitration of p-nitrochlorobenzene with a mixture of nitric and sulfuric acids. Other methods afford the compound less efficiently include the chlorination of 1,3-dinitrobenzene, nitration of o-nitrochlorobenzene and the dinitration of chlorobenzene.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. For example, the chloride can be replaced by iodide easily.
Reaction of DNCB with ammonia gives 2,4-dinitrochloroaniline, again a versatile precursor.
DNCB is as a substrate in glutathione S-transferase, relevant to activity assays.
Safety
DNCB induces a type [IV hypersensitivity] reaction in almost all people exposed to it, so it is used medically to assess the T cell activity in patients. This is a useful diagnostic test for immunocompromised patients. It can also be used to treat warts.DNCB can cause contact dermatitis.