Debus-Radziszewski imidazole synthesis
The Radziszewski synthesis is a name reaction in organic chemistry and named after the Polish chemist Bronisław Leonard Radziszewski. It describes the preparation of imidazole and its derivatives. For this purpose a 1,2- diketone is reacted with ammonia and an aldehyde.
Reaction mechanism
Of 1,2- diketones, ammonia, and aldehyde, the corresponding imidazole is shown. This mechanism occurs in two major reaction steps, which are described below.
First step
In the first step, ammonia is ever attached to each of the diketone and a keto group at the same time split off water. The result is a diimine, so a Schiff base.
Second Step
This is followed by an attack of the imine to the carbonyl group of the aldehyde. It forms the desired imidazole.