Artificial Alizarin

Researchers worked to determine the structures of important natural dyes in order to synthesize them. Until then, chemists such as Perkin operated through trial and error. Once chemists understood the tetravalency of carbon and the nature of the benzene ring, they were able to deduce the molecular structures of the well-known natural dyes (indigo and alizarin) and the new synthetics (mauve, magenta and azo dyes). German chemists Carl Graebe and Carl Liebermann first successfully synthesized an artificial alizarin, derived from coal-tar anthracene, in 1868.