Hydroxy-6-heteroarylphenanthridines and their use as PDE4 inhibitors

1. A method of treating psoriasis in a patient, comprising administering to said patient a compound of formula Ia*****

wherein

R1 is methoxy,

R2 is methoxy, ethoxy, difluoromethoxy or 2,2-difluoroethoxy,

R3 is hydrogen,

R31 is hydrogen,

R41 is hydrogen,

R5 is hydrogen,

Har is substituted by R6 and R7, and is pyridinyl, in which

R6 is oxo, and

R7 is methyl,

or a pharmaceutically acceptable salt thereof.

2. The method of treating psoriasis in a patient according to claim 1 , comprising administering to said patient a compound of formula Ia*****,

wherein

R1 is methoxy,

R2 is methoxy, ethoxy, difluoromethoxy or 2,2-difluoroethoxy,

R3 is hydrogen,

R31 is hydrogen,

R41 is hydrogen,

R5 is hydrogen,

Har is 1-methyl-1H-pyridin-2-one-5-yl,

or a pharmaceutically acceptable salt thereof.

3. The method of treating psoriasis in a patient according to claim 1 , comprising administering to said patient a compound of formula Ia*****,

wherein

R1 is methoxy,

R2 is ethoxy, difluoromethoxy or 2,2-difluoroethoxy,

R3 is hydrogen,

R31 is hydrogen,

R41 is hydrogen,

R5 is hydrogen,

Har is 1-methyl-1H-pyridin-2-one-5-yl,

or a pharmaceutically acceptable salt thereof.

4. The method of treating psoriasis in a patient according to claim 1 , comprising administering to said patient a compound of formula Ia*****, which is selected from the group consisting of 5-((2R,4aR,10bR)-9-Ethoxy-2-hydroxy-8-methoxy-1,2,3,4,4a,10b-hexahydro-phenanthridin-6-yl)-1-methyl-1H-pyridin-2-one and a pharmaceutically acceptable salt thereof.

5. The method of treating psoriasis in a patient according to claim 1 , comprising administering to said patient a compound of formula Ia*****, which is 5-((2R,4aR,10bR)-9-Ethoxy-2-hydroxy-8-methoxy-1,2,3,4,4a,10b-hexahydro-phenanthridin-6-yl)-1-methyl-1H-pyridin-2-one.