Novel hydroxy-6-heteroarylphenanthridines and their use as pde4 inhibitors

A compound of formula Ia*****

• in which
• R1 is 1-2C-alkoxy, 2,2-difluoroethoxy, or completely or predominantly fluorine-substituted 1-2C-alkoxy,
• R2 is 1-2C-alkoxy, 2,2-difluoroethoxy, or completely or predominantly fluorine-substituted 1-2C-alkoxy,
• R3 is hydrogen,
• R31 is hydrogen,
• R41 is hydrogen,
• R5 is hydrogen,
• Har is optionally substituted by R6 and/or R7 and is a pyridinyl, isoxazolyl, imidazolyl, thiazolyl, oxazolyl, pyrimidinyl, pyrazinyl or pyridazinyl radical, in which
• R6 is 1-4C-alkyl, 1-4C-alkoxy, pyridyl or morpholin-4-yl,
• R7 is 1-4C-alkoxy,
• or a salt of this compound.