(R)-4-(heteroaryl) phenylethyl derivatives and pharmaceutical compositions containing them

(R)-4-(heteroaryl)phenylpropionic compounds of formula (I):

• and pharmaceutically acceptable salts thereof, wherein
• X is a heteroatom selected from
• S, O and N
• Y is H or a residue selected from the group consisting of:
• halogen, linear or branched C1-C4-alkyl, C2-C4-alkenyl, C1-C4-alkoxy, hydroxy, —COOH, C1-C4-acyloxy, phenoxy, cyano, nitro, —NR2, C1-C4-acylamino, halo-C1-C3-alkyl, benzoyl, linear or branched C1-C8-alkanesulfonate, linear or branched C1-C8-alkanesulfonamides, linear or branched C1-C8-alkyl sulfonylmethyl;
• Z is an heteroaryl ring selected from the group consisting of:
• unsubstituted tetrazole and
• triazole, pyrazole, oxazole, thiazole, isooxazole, isothiazole, thiadiazole and oxadiazole substituted by one hydroxy group and optionally further substituted by one or more goups selected from the group consisting of halogen, linear or branched C1-C4-alkyl, C2-C4-alkenyl, C1-C4-alkylamino, C1-C4-alkoxy, C1-C4-alkylthio, C1-C4-acyloxy, cyano, nitro, NH2, C1-C4-acylamino, halo-C1-C3-alkyl, halo-C1-C3-alkoxy, linear or branched C1-C8-alkanesulfonate and linear or branched C1-C8-alkanesulfonamides.