Derivatives of (hetero)aromatic ethers and thioethers having antihyperlipidemic activity, process for their preparation and pharmaceutical compositions containing them

A compound represented by the following formula I:

• (HET)Ar--X--CH.sub.2 --Y--CH.sub.2 --O--R (I)
• wherein:
• (HET) Ar represents a bicyclic nucleus consisting of fused 6-5 membered rings, the 6-membered ring containing 2 nitrogen atoms in the relative positions 1-3, the 5-membered ring containing two nitrogen heteroatoms also in the relative positions 1-3, the bicyclic nucleus bearing one to three substituents, identical to or different from each other, selected from the group consisting of straight chain C.sub.1 -C.sub.5 alkyl, branched chain C.sub.1 -C.sub.5, alkyl, NH.sub.2, --OH, lower alkoxy, phenyl, and halogen, X represents --S--;
• Y represents --CO--, --C.dbd.N--R.sub.2, in which R.sub.2 is OH, an alkoxy having 1 to 10 carbon atoms, aryloxy, arylalkoxy, --NH.sub.2, --NHCONH.sub.2, --NHCSNH.sub.2 ;
• and R represents a phenyl substituted at para position with a carboxyl or a (C.sub.1 -C.sub.20) alkoxycarbonyl group in which the alkoxy group is linear or branched.