A method for preparing an imidazole compound with the following formula: wherein Rf is a fluorinated alkyl group comprising between 1 and 5 carbon atoms, said method including: (a) the reaction of the diaminomaleonitrile with the following formula: with the compound with the following formula: wherein Y represents a chlorine atom or the OCORf group to form the salified amide compound with the following formula: at temperature T1, and (b) the dehydration of the salified amide compound with formula (IVa) and/or the corresponding amino (IVb) to form the imidazole compound with formula (III), at temperature T2 higher than T1.