Abbreviations CDNB; DNCB Density 1.687 g/cm³ Appearance yellow crystals | Formula C6H3ClN2O4 Boiling point 315 °C | |
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2,4-Dinitrochlorobenzene (DNCB) is an organic compound with the formula (O2N)2C6H3Cl. It is a yellow solid that is soluble in organic solvents. It is an important intermediate for the industrial production of other compounds.
Contents
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 dinitrobenzene, nitration of o-nitrochlorobenzene and the dinitration of chlorobenzene.
Uses
By virtue of the two nitro groups, the chloride is susceptible to nucleophilic substitution. In this way, the compound is a precursor to many other compounds. Base gives the dinitrophenol, ammonia the dinitroaniline, methoxide the dinitroanisole, and amines the secondary amines.
Laboratory use
DNCB is used as a substrate in GST enzyme activity assays. The molecule is conjugated to a single molecule of reduced glutathione which then absorbs at 340 nm. Affinity of CDNB for each class of GST varies and so it is not a good measure of activity for some forms (e.g. GSTT and GSTZ).
Medical use
DNCB can be used to treat warts with an effective cure rate of 80%. DNCB induces an allergic immune response toward the wart-causing virus.
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.