The present invention concerns novel compounds of formula (I). wherein R1 is C1-10alkyl, C3-7cycloalkyl or C1-6alkyl substituted with C3-7cycloalkyl; R2 is hydrogen or C1-6alkyl; Alk represents C1-3alkanediyl; —A— represents a bivalent radical of formula —CH═CH—N═CH— (a), —N═CH—N═CH— (b), —CH═N—N═CH— (c), —CH═CH—CH═N— (d); in said bivalent radicals a hydrogen atom may be replaced by C1-6alkyl; and Ar is unsubstituted phenyl; phenyl substituted with up to two substituents selected from halo, C1-6alkyl or C1—6alkyloxy; unsubstituted naphthyl; or naphthyl substituted with up to two substituents selected from halo, C1-6alkyl or C1-6alkyloxy; the stereochemically isomeric forms thereof, and the pharmaceutically acceptable acid addition salts thereof. The present invention further comprises the pharmaceutical compositions comprising compounds of formula (I), the preparation thereof as well as the use as a medicine in the treatment of hyperlipidemia.