Abstract: The invention relates to a process for preparing an asymmetrical imidazolium salt of formula (1A), in which R1 is an aromatic group, R2 is chosen from a cyclic secondary aliphatic alkyl group and a heteroalkyl group, R3 and R4 are chosen, independently of one another, from the group consisting of hydrogen, a halide and an alkyl group, and A? is an anion. The process comprises a first substep of forming a reaction mixture by bringing one equivalent of an aniline into contact with one equivalent of a compound bearing an amine group, in the presence of at least four point five equivalents of a Brønsted acid. The process also comprises a second substep of forming a solution comprising one equivalent of a dicarbonyl, one equivalent of formaldehyde, and at least four point five equivalents of the Brønsted acid, and adding thereto the reaction mixture formed in the first substep. The mixture is left to stir for a predetermined time at a predetermined temperature.

Abstract: The invention relates to a process for preparing an asymmetrical imidazolium salt of formula (1A), in which R1 is an aromatic group, R2 is chosen from a cyclic secondary aliphatic alkyl group and a heteroalkyl group, R3 and R4 are chosen, independently of one another, from the group consisting of hydrogen, a halide and an alkyl group, and A? is an anion. The process comprises a fast substep of forming a reaction mixture by bringing one equivalent of an aniline into contact with one equivalent of a compound bearing an amine group, in the presence of at least four point five equivalents of a Brønsted acid. The process also comprises a second substep of forming a solution comprising one equivalent of a dicarbonyl, one equivalent of formaldehyde, and at least four point five equivalents of the Brønsted acid, and adding thereto the reaction mixture formed in the first substep. The mixture is left to stir for a predetermined time at a predetermined temperature.