Compounds of formula Iin whichR1 is methoxy,R2 is methoxy, ethoxy, difluoromethoxy or 2,2-difluoroethoxy,R3 is hydrogen,R31 is hydrogen,R4 is -O-R41, in whichR41 is hydrogen,R5 is hydrogen,Har is substituted by R6 and R7, and is pyridinyl, in whichR6 is oxo, andR7 is methyl,or an enantiomer, a salt, a N-oxide or a salt of an enantiomer or N-oxide thereofare novel effective PDE4 inhibitors.