• Source: 2-Nitrochlorobenzene

2-Nitrochlorobenzene is an organic compound with the formula ClC6H4NO2. It is one of three isomeric nitrochlorobenzenes. It is a yellow crystalline solid that is important as a precursor to other compounds due to its two functional groups.




Synthesis


Nitrochlorobenzene is typically synthesized by nitration of chlorobenzene in the presence of sulfuric acid:

C6H5Cl + HNO3 → O2NC6H4Cl + H2O
This reaction affords a mixture of isomers. Using an acid ratio of 30% nitric acid, 56% sulfuric acid and 14% water, the product mix is typically 34-36% 2-nitrochlorobenzene and 63-65% 4-nitrochlorobenzene, with only about 1% 3-nitrochlorobenzene.




Reactions


2-Nitrochlorobenzene can be reduced to the 2-chloroaniline with Fe/HCl mixture, the Bechamp reduction.
2-Nitrochlorobenzene, like its isomers, is reactive toward nucleophiles, resulting in chloride substitution. With polysulfide, it reacts to give di-orthonitrophenyl disulfide:

2 O2NC6H4Cl + Na2S2 → (O2NC6H4S)2 + 2 NaCl
Similarly, it reacts with sodium methoxide to give 2-nitroanisole.
Substitution of chloride by fluoride is also practiced commercially to convert 2-nitrochlorobenzene to 2-fluoronitrobenzene. The Halex process uses potassium fluoride in polar solvents like sulfolane :

O2NC6H4Cl + KF → O2NC6H4F + KCl




Applications


2-Nitrochlorobenzene is useful because both of its reactive sites can be utilized to create further compounds that are mutually ortho. Its derivative 2-chloroaniline is a precursor to 3,3’-dichlorobenzidine, a precursor to dyes and pesticides.




References

Kata Kunci Pencarian:

• 2-Nitrochlorobenzene
• Nitrochlorobenzene
• 4-Nitrochlorobenzene
• 3-Nitrochlorobenzene
• 2-Fluoronitrobenzene
• 2-Nitroaniline
• Chlorobenzene
• Aryl halide
• Halex process
• O-Phenylenediamine