Coal Extracts quinones

Quinones are colored p-benzoquinone, for exanple, is yellow. Many occur naturally and have been used as dyes. Alizarin is a red pigment extracted from the roots of the madder plant. Its preparation from anthracene, a coal tar derivative, in 1868 was a significant step in the development of the synthetic dyestuff industry. 

Oxidative degradation of the o-quinone (429), obtained by chromic acid oxidation of the corresponding benzofuran (extracted from coal... 

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