The invention relates to compounds of the formula (I) where: R is a (C1-C6)alkyl group, a halo(C1-C6)alkyl group; R1 is a hydrogen atom; R2 is a heterocyclic group bound by a carbon atom, a heterocyclic-(C1-C4)alkyl group, said groups being optionally substituted; R3 and R4 represent independently from each other an optionally substituted phenyl group; X is a hydrogen atom, a halogen, a cyano, a (C1-C6)alkyl group, a halo(C1-C6)alkyl group, a (C1-C6)alkoxy group, a halo(C1-C6)alkoxy group or a (C1-C6)alkylS(0)p group; and p is 0 to 2. The invention also relates to a method for preparing same and to the therapeutic application thereof.