4-aryl-thiazol- eller -imidazolderivater

The invention concerns a 4-aryl-thiazole or imidazole derivative having the formula I wherein X is O or NOH, Y is S or NR3, Ar is a group selected from phenyl, naphthyl, tetrahydronaphthyl, and biphenyl, R is one to four substituents independently selected from hydrogen, hydroxy, lower alkyl, lower alkoxy, lower thioalkyl, cycloalkyl, halogen, CF3, NO2, and O-ALK-NR1R2, in which ALK is a saturated aliphatic hydrocarbon group having 2-6 carbon atoms, and R1 and R2 are independently hydrogen or lower alkyl, or form, together with the nitrogen atom to which they are bonded, a heterocyclic ring, and R3 is hydrogen or a lower alkyl; or a pharmaceutically acceptable salt thereof, with the proviso that 4-(4-chlorophenyl)-thiazole-2-carboxamide is excluded. The compounds according to the invention increase the sensitivity of cardiac myofibrils to calcium and possess phosphodiesterase inhibitory activity and bronchodilator activity, and are useful for the treatment of patients suffering from heart failure and asthma.