4-Nitrotoluene Explained

4-Nitrotoluene or para-nitrotoluene is an organic compound with the formula CH₃C₆H₄NO₂. It is a pale yellow solid. It is one of three isomers of nitrotoluene.

Synthesis and reactions

Together with other isomers, 4-nitrotoluene is prepared by nitration of toluene, commonly using titanium(IV) nitrate.^[1] It undergoes the reactions typical for nitrobenzene derivatives, e.g. hydrogenation gives p-toluidine.

Oxidation of the methyl substituent of 4-nitrotoluene has been extensively investigated. Depending on the conditions, oxidation yields 4-nitrobenzaldehyde diacetate,^[2] 4-nitrobenzenoic acid,^[3] and 4,4'-dinitrobibenzyl.^[4] Treatment of 4-nitrotoluene with bromine gives the 4-nitrobenzyl bromide.^[5]

Applications

The principal application involves its sulfonation to give the 4-nitrotoluene-2-sulfonic acid (with the  - SO₃H group adjacent to methyl). This species can be oxidatively coupled to produce stilbene derivatives,^[6] which are used as dyes. Representative derivatives include the molecular and salt forms of 4,4'-dinitroso- and the 4,4'-dinitro-2,2'-stilbenedisulfonic acids, e.g. disodium 4,4'-dinitrostilbene-2,2'-disulfonate.^[7]

Safety

Evidence exists for toxicity and carcinogenicity in mice.^[8]

External links

• CDC – NIOSH Pocket Guide to Chemical Hazards – p-Nitrotoluene

Notes and References

1. Amos. D.W.. D.A. Baines, G.W. Flewett. 1973. Nitration by titanium (IV) nitrate. Tetrahedron Letters. 14. 34. 3191–3194. 0040-4039. 10.1016/S0040-4039(00)79808-X.
2. 10.15227/orgsyn.036.0058. o- and p-Nitrobenzaldiacetate. Tamio Nishimura . Organic Syntheses . 1956 . 36 . 58 .
3. 10.15227/orgsyn.002.0053. p-Nitrobenzoic Acid. O. Kamm, A. O. Matthews . Organic Syntheses . 1922 . 2 . 53 .
4. 10.15227/orgsyn.034.0035. p,p'-Dinitrobibenzyl . Organic Syntheses . 1954 . 34 . 35. Herbert O. House.
5. 10.15227/orgsyn.016.0054. p-Nitrobenzyl Bromide . Organic Syntheses . 1936 . 16 . 54. G. H. Coleman, G. E. Honeywell.
6. Book: Systematic Organic Chemistry: Modern Methods of Preparation and Estimation. 1926. William M.. Cumming. I. Vance. Hopper. T. Sherlock. Wheeler. 314. D. Van Nostrand Company. New York. Preparation 294. - Dinitro-Stilbene-Disulphonic Acid (Na salt). https://archive.org/details/systematicorgani00cumm_0.
7. Encyclopedia: Gerald Booth. Nitro Compounds, Aromatic. Ullmann's Encyclopedia of Industrial Chemistry. 2007. Wiley-VCH. Weinheim. 10.1002/14356007.a17_411. 978-3527306732.
8. 12118261 . 2002 . National Toxicology . Program . Toxicology and carcinogenesis studies of p-nitrotoluene (CAS no. 99-99-0) in F344/N rats and B6C3F(1) mice (feed studies) . 498 . 1–277 . National Toxicology Program Technical Report Series.