Compounds of general formula ##STR1##

in which X represents an oxygen atom or a group of formula NZ in which Z represents a hydrogen atom or an alkyl group, n represents a number 0, 1 or 2, and R₁, R₂, R₃, R₄ and R₅ each represent a hydrogen or halogen atom or a trifluoromethyl, trifluoromethoxy, cyano, hydroxyl, alkyl, alkoxy, phenoxy or phenyl group optionally substituted with a halogen atom or a trifluoromethyl, cyano, hydroxyl, alkyl or alkoxy group, or alternatively R₂ and R₃ together form a group of formula —OCH₂O— or —CH₂CH₂CH₂CH₂—.

Application in therapy.