Bucherer-Bergs hydantoin synthesis

What is Bucherer-Bergs hydantoin synthesis?

In 1905, Ciamician and Silber were the first to observe the reaction that produced 5,5-dimethylhydantoin from a mixture of acetone and hydrocyanic acid exposed to sunlight for 5-7 months.

Bucherer-Bergs hydantoin synthesis - general reaction scheme
Bucherer-Bergs hydantoin synthesis

Later on, Bergs developed a method for preparing 5-substituted hydantoins from aldehydes or ketones using potassium cyanide, ammonium carbonate, and carbon dioxide, while Bucherer modified Bergs‘ procedure for synthesizing hydantoin from cyanohydrin and ammonium carbonate in an aqueous solution or benzene at temperatures below 60-70 ºC, and studied the mechanism, leading to the reaction being commonly known as the Bucherer-Bergs reaction.

Bucherer-Bergs hydantoin synthesis - general reaction scheme - Bucherer-Bergs reaction
Bucherer-Bergs reaction

The reaction has also been further modified by Henze. The Bucherer-Bergs hydantoin synthesis involves the preparation of hydantoin from carbonyl compounds using potassium cyanide and ammonium carbonate or from the corresponding cyanohydrin and ammonium carbonate, and is an example of multicomponent reactions (MCRs), although certain carbonyl compounds are unsuitable for this reaction.

Hydantoin itself has many biological activities, such as anticonvulsants, antiarrhythmics, antidiabetics, and serotonin and fibrinogen receptor antagonists, and is used as a starting material for preparing various α-amino acids through hydrolysis.