A compound corresponding to general formula (I): ##STR00001## in which R.sub.1 represents a phenyl or naphthalenyl group optionally substituted with one or more halogen atoms or hydroxyl, cyano, nitro, (C.sub.1 C.sub.3)alkyl, (C.sub.1 C.sub.3)alkoxy, trifluoromethyl, trifluoromethoxy, benzyloxy, (C.sub.3 C.sub.6)cycloalkyl-O-- or (C.sub.3 C.sub.6)cycloalkyl(C.sub.1 C.sub.3)alkoxy groups; R.sub.2 represents either a group of general formula CHR.sub.3CONHR.sub.4 in which R.sub.3 represents a hydrogen atom or a methyl group and R.sub.4 represents a hydrogen atom or a (C.sub.1 C.sub.3)alkyl, (C.sub.3 C.sub.5)cycloalkyl or (pyridin-4-yl)methyl group; or a 2,2,2-trifluoroethyl group; or an (imidazol-2-yl)methyl group; or a (benzimidazol-2-yl)methyl group; or a phenyl group optionally substituted with one or more halogen atoms or cyano, nitro, (C.sub.1 C.sub.3)alkyl, (C.sub.1 C.sub.3)alkoxy, trifluoromethyl or trifluoromethoxy groups; and n represents a number ranging from 1 to 3; in the form of a base, of an addition salt with an acid, of a hydrate or of a solvate. Also disclosed and claimed are the pharmaceutical compositions derived therefrom and their therapeutic use in treating a wide variety of diseases.