Bohn-Schmidt reaction

What is Bohn-Schmidt reaction?

In 1889, Bohn first reported a reaction that was later reported by Schmidt in 1891. This reaction, known as the Bohn-Schmidt reaction, involves introducing hydroxyl groups into anthraquinone molecules that have at least one hydroxyl group by using fuming sulfuric acid H2SO4 as an oxidizing agent.

Bohn-Schmidt reaction
Bohn-Schmidt reaction

It has been documented that the addition of boric acid H3BO3 to the reaction mixture can enable the use of ordinary concentrated sulfuric acid instead of fuming, and that boric acid H3BO3 can form esters with hydroxyanthraquinones to prevent further oxidation. Furthermore, selenium, selenium oxide SeO3, and mercury can be utilized as catalytic agents.

The Bohn-Schmidt reaction has been employed in the industrial production of significant dyes, including alizarin green S, alizarin bordeaux, alizarin cyanine R, and alizarin cyanin black.

References

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