Novel heterocycle-substituted hydroxy-6-phenylphenanthridines and their use as pde4 inhibitors

A compound of formula I

• in which
• R1 is hydroxyl, 1-4C-alkoxy, 3-7C-cycloalkoxy, 3-7C-cycloalkylmethoxy, 2,2-difluoroethoxy, or completely or predominantly fluorine-substituted 1-4C-alkoxy,
• R2 is hydroxyl, 1-4C-alkoxy, 3-7C-cycloalkoxy, 3-7C-cycloalkylmethoxy, 2,2-difluoroethoxy, or completely or predominantly fluorine-substituted 1-4C-alkoxy,
• 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,
• either, in a first embodiment (embodiment a),
• R4 is —O—R41, in which
• R41 is hydrogen, 1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl, hydroxy-2-4C-alkyl, 1-7C-alkylcarbonyl, or completely or predominantly fluorine-substituted 1-4C-alkyl, and
• R5 is hydrogen or 1-4C-alkyl,
• or, in a second embodiment (embodiment b),
• R4 is hydrogen or 1-4C-alkyl, and
• R5 is —O—R51, in which
• R51 is hydrogen, 1-4C-alkyl, 1-4C-alkoxy-1-4C-alkyl, hydroxy-2-4C-alkyl, 1-7C-alkylcarbonyl, or completely or predominantly fluorine-substituted 1-4C-alkyl,
• R6 is hydrogen, halogen, 1-4C-alkyl or 1-4C-alkoxy,
• R7 is Het1, Het2, Har1, Het3 or Har2, in which
• Het1 is optionally substituted by R71 and is a monocyclic 3- to 7-membered fully saturated heterocyclic ring radical comprising one to three heteroatoms independently selected from the group consisting of nitrogen, oxygen and sulfur, in which
• R71 is 1-4C-alkyl, 1-4C-alkoxy, or completely or partially fluorine-substituted 1-4C-alkyl,
• Het2 is optionally substituted by R72 and is a monocyclic 5- to 7-membered saturated or unsaturated heterocyclic ring radical, which comprises one nitrogen atom and optionally one or two further heteroatoms independently selected from the group consisting of nitrogen, oxygen and sulfur, and to which ring one or two oxo substituents are bonded, in which
• R72 is 1-4C-alkyl, 1-4C-alkoxy, or completely or partially fluorine-substituted 1-4C-alkyl,
• Har1 is optionally substituted by R73 and is a monocyclic 5-membered fully unsaturated heterocyclic ring radical comprising one to four heteroatoms independently selected from the group consisting of nitrogen, oxygen and sulfur, in which
• R73 is 1-4C-alkyl, 1-4C-alkoxy, or completely or partially fluorine-substituted 1-4C-alkyl,
• Het3 is optionally substituted by R74 and is a monocyclic 5- or 6-membered partially unsaturated heterocyclic ring radical comprising one nitrogen atom and optionally one further heteroatom selected from the group consisting of nitrogen, oxygen and sulfur, in which
• R74 is 1-4C-alkyl, 1-4C-alkoxy, or completely or partially fluorine-substituted 1-4C-alkyl,
• Har2 is optionally substituted by R75 and/or R76 and stands for a monocyclic 6-membered fully unsaturated heterocyclic ring radical comprising one to three nitrogen atoms, in which
• R75 is 1-4C-alkyl, 1-4C-alkoxy, 1-4C-alkylthio, halogen, hydroxyl, amino, mono- or di-1-4C-alkylamino, or completely or partially fluorine-substituted 1-4C-alkyl,
• R76 is 1-4C-alkoxy, 1-4C-alkylthio, hydroxyl, amino or mono- or di-1-4C-alkylamino,
• or a salt, enantiomer, N-oxide, salt of an N-oxide or enantiomer thereof.