| abstract |
Compounds of formula 1, in which Het is an unsubstituted or R6- and/or R7-substituted pyrrolyl, furanyl, thiophenyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyrimidinyl, pyrazinyl or pyradazinyl radical, or an unsubstituted or R6- and/or R7-substituted fused bi- or tricyclic ring system comprising at least one aromatic ring and up to 4 heteroatoms-selected from the group consisting of O (oxygen), S (sulfur), N (nitrogen)- which is bonded to the phenanthridinyl radical via one of the rings comprising one or more heteroatoms, are active PDE4 inhibitors. |