2-hydroxy-6-phenylphenanthridines as PDE-4.

Compounds of formula I, in which R1 is hydroxyl, 1-4C-alkoxy, 3-7C-cycloalkoxy, 3-7C-cycloalkylmethoxy, or 1-4C alkoxy full or predominantly substituted by fluorine, R2 is hydroxyl, 1-4C-alkoxy, cycloalkoxy 3-7C, 3-7C-cycloalkylmethoxy, or 1-4C-alkoxy completely or predominantly substituted by fluorine, or in which R1 and R2 together are a 1-2C-alkylenedioxy group, R3 is hydrogen or 1-4C alkyl, R31 is hydrogen or 1-4C alkyl, R4 is hydrogen, 1-4C alkyl, 1-4C Total alkyl or predominantly substituted by fluorine, 1-4C-alkyl coxi al 1-4C, 2-4C alkyl or hydroxy-1-7C-alkylcarbonyl, R5 is hydrogen or C1-4 alkyl, R6 is hydrogen, C1-4 alkyl, trifluoromethyl, C1-4 alkoxy, C1-4 alkyl or alkoxy Total predominantly substituted by fluorine, 3-7C-cycloalkoxy, 3-7C-cycloalkylmethoxy, halogen, nitro , cyano, hydroxyl, alkylcarbonyloxy 1-4C, amino, mono- or di-1-4C, phenyl, phenyl-alkyl 1- 4C, 1-4C alkylcarbonylamino, phenoxy or C (O) OR61, wherein R61 is Hydrogen not, 1-7C alkyl, 3-7C cycloalkyl or 3-7C-cycloalkylmethyl, R7 is hydrogen, 1-4C alkyl, hydroxyl, halogens not, C1-4 alkoxy, C1-4 alkyl or alkoxy Total predominantly substituted by fluorine, 3- 7C-cycloalkoxy, 3-7C-cycloalkylmethoxy or C (O) OR61, and the salts, the N-oxides and the salts of the N-oxides of these compounds.