Chemistry:2-Nitrochlorobenzene
2-Nitrochlorobenzene is an organic compound with the formula ClC6H4NO2. It is one of three isomeric nitrochlorobenzenes.[1] 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.[1]
Reactions
2-Nitrochlorobenzene can be reduced to the 2-chloroaniline with Fe/HCl mixture, the Bechamp reduction.[1]
2-Nitrochlorobenzene, like its isomers, is reactive toward nucleophiles, resulting in chloride substitution. With polysulfide, it reacts to give di-orthonitrophenyl disulfide:[2]
- 2 O
2NC
6H
4Cl + Na
2S
2 → (O
2NC
6H
4S)
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 :
- O
2NC
6H
4Cl + KF → O
2NC
6H
4F + 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.
Some of the recognized uses of 2-nitrochlorobenzene include in the synthesis loxapine,[3] quetiapine,[4] amoxapine,[5] clotiapine, metiapine & methopromazine.[6]
References
- ↑ 1.0 1.1 1.2 Booth, Gerald (2000). "Nitro Compounds, Aromatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411. ISBN 978-3-527-30385-4.
- ↑ Bogert, Marston T.; Stull, Arthur (1928). "Di-o-Nitrophenyl Disulfide". Organic Syntheses 8: 64. doi:10.15227/orgsyn.008.0064.
- ↑ Strategies for organic drug synthesis and design (2nd ed.). Wiley. 2009. ISBN 9780470190395.
- ↑ "Synthesis of 11-14C-quetiapine, 11-14C-isoclotiapine and 10-(4-methylpiperazin-1-yl)pyrido[4,3-b[1,4]benzothiazepine[10-14C]"]. Journal of Radioanalytical and Nuclear Chemistry 310 (1): 433–439. October 2016. doi:10.1007/s10967-016-4798-1. http://link.springer.com/10.1007/s10967-016-4798-1. Retrieved 28 August 2026.
- ↑ "Amoxapine". Drugs of the Future 1 (11): 511. 1976. doi:10.1358/dof.1976.001.11.313544. ISSN 0377-8282. http://journals.prous.com/journals/servlet/xmlxsl/pk_journals.xml_summary_pr?p_JournalId=2&p_RefId=313544&p_IsPs=N. Retrieved 28 August 2026.
- ↑ Charpentier, P. et al, C.R. Hebd. Seances Acad. Sci., 1952, 235, 59.
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