The present invention relates to compounds of the formula ##STR1## wherein R represents hydrogen; C.sub.1-6 alkyl; C.sub.3-6 cycloalkyl; phenyl optionally substituted with from 1 to 3 substituents each independently selected from halo, hydroxy, C.sub.1-6 alkyloxy, C.sub.5-6 cycloalkyloxy, C.sub.1-6 alkyl or trifluoromethyl; pyridinyl; or thienyl optionally substituted with halo or C.sub.1-6 alkyl; and .dbd.C.dbd.X is a radical of the formula: .dbd.C.dbd.O (a), .dbd.C.dbd.N--O--R.sup.1 (b), or .dbd.C.dbd.CH--R.sup.2 (c); the addition salts thereof and stereochemically isomeric forms thereof, said compounds being useful as intermediate to potent inhibitors of both phosphodiesterase III and IV, which are useful in the treatment of warm-blooded animals suffering from allergic disorders, atopic diseases and related afflications.
Novel 1,3-dihydro-2H-imidazo[4,5-b]quinolin-2-one derivatives of formula ##STR1## wherein R is hydrogen, C.sub.1-6 alkyl, C.sub.3-6 cycloalkyl, phenyl optionally substituted with from 1 to 3 substituents each independently selected from halo, hydroxy, C.sub.1-6 alkyloxy, C.sub.5-6 cycloalkyloxy, C.sub.1-6 alkyl or trifluoromethyl; pyridinyl; thienyl optionally substituted with halo or C.sub.1-6 alkyl; and >C.dbd.X is a radical of formula >C.dbd.O (a), >C.dbd.N--O--R.sup.1 (b), or >C.dbd.CH--R.sup.2 (c); the pharmaceutically acceptable addition salts and stereochemically isomeric forms thereof, said compounds being potent inhibitors of both phosphodiesterase III and IV, which are useful in the treatment of allergic disorders, atopic diseases and related afflictions. Intermediates in the preparation thereof. Pharmaceutical compositions containing said compounds as an active ingredient. Methods of preparing said compounds and pharmaceutical compositions.