2-Methylanthraquinone Explained

2-Methylanthraquinone, also known as β-methylanthraquinone and tectoquinone,^[1] is an organic compound which is a methylated derivative of anthraquinone. An off-white solid, it is an important precursor to many dyes. It is present in the wood of the teak tree, where it gives the tree resistance to insects.^[2]

Synthesis and reactions

The compound is produced by the reaction of phthalic anhydride and toluene.^{[3] [4]} It can be chlorinated to give 1-chloro-2-methylanthraquinone. Nitration gives 1-nitro-2-methylanthraquinone, which can be reduced to 1-amino-2-methyl derivative. Oxidation of the methyl group gives anthraquinone-2-carboxylic acid.^[5]

References

1. Web site: 2-Methylanthraquinone . CAS Common Chemistry . 5 August 2023.
2. Rudman . P. . Da Costa . E. W. B. . Gay . F. J. . Wetherly . A. H. . Relationship of tectoquinone to durability in Tectona grandis . Nature . 8 March 1958 . 181 . 4610 . 721–722 . 10.1038/181721b0. 1958Natur.181..721R . 4159998 .
3. L. F. Fieser. 10.15227/orgsyn.004.0073. p-Toluyl-o-Benzoic Acid. Organic Syntheses. 4. 73. 1925.
4. L. F. Fieser. 10.15227/orgsyn.004.0043. β-Methylanthraquinone. Organic Syntheses. 4. 43. 1925.
5. Book: 10.1002/14356007.a02_355. Anthraquinone Dyes and Intermediates. Ullmann's Encyclopedia of Industrial Chemistry. 2000. Bien. Hans-Samuel. Stawitz. Josef. Wunderlich. Klaus. 3-527-30673-0.