Chalcone is the organic compound C<sub>6</sub>H<sub>5</sub>C(O)CH=CHC<sub>6</sub>H<sub>5</sub>. It is an ñ,ò-unsaturated ketone. A variety of important biological compounds are known collectively as chalcones or chalconoids. They are widely known bioactive substances, fluorescent materials, and chemical intermediates.
Chalcones have two absorption maxima at 280 nm and 340 nm.
Chalcones and chalconoids are synthesized in plants as secondary metabolites. The enzyme chalcone synthase, a type III polyketide synthase, is responsible for the biosynthesis of these compounds. The enzyme is found in all "higher" (vascular) and several "lower" (non-vascular) plants.
Chalcone is usually prepared by an aldol condensation between benzaldehyde and acetophenone.
This reaction, which can be carried out without any solvent, is so reliable that it is often given as an example of green chemistry in undergraduate education.
Chalcones and their derivatives demonstrate a wide range of biological activities including anti-inflammation. Some 2â²-amino chalcones have been studied as potential antitumor agents. Chalcones are of interest in medicinal chemistry and have been described as a privileged scaffold.
In medicinal chemistry, chalcones have been used as:
In chemical industries, they are employed as:
Chalcones have been used as intermediates in heterocyclic synthesis, especially in the synthesis of pyrazoles and aurones.
In the JohnsonâÂÂCoreyâÂÂChaykovsky reaction, chalcone reacts with dimethylsulfoxonium methylide to give 1-phenyl-2-benzoylcyclopropane [15295-43-9] [1145-91-1] in 95% yield. A Leuckart reaction or ammonium acetate in the presence of sodium cyanoborohydride would be predicted to give Phenyl(2-phenylcyclopropyl)methanamine [1559116-96-9]. Alternatively if a reductive amination of the ketone with methylamine is performed one would instead get the secondary amine N-Me [1559367-56-4].
These compounds have the same trans-stereochemistry as was observed for tranylcypromine although their exact mode of pharmacology is still lacking. Lastly, it was discovered that if a hydrazine is prepared from the ketone (ala pheniprazine) one gets a compound that is called [Phenyl-(2-phenylcyclopropyl)methyl]hydrazine (PC105199424).