The Debus-Radziszewski imidazole synthesis is an organic reaction describing the synthesis of an imidazole from a diketone, an aldehyde and ammonia. It is an example of a multicomponent reaction.
In step one the diketone and ammonia form an diimine:
In the second step the diimine condenses with the aldehyde:
This reaction is named after Heinrich Debus[1] and Bronisław Leonard Radziszewski [2][3]
A modification of this general method, where one equivalent of ammonia is replaced by an amine, affords N-substituted imidazoles in good yields.[4]