abstract |
There is provided compounds of formula I,n nwherein R 1 , R 2 , R 3 and Het 1 have meanings given in the description, whichnare useful in the curative and prophylactic treatment of medical conditionsnfor which inhibition of a cyclic guanosine 3',5'-monophosphatenphosphodiesterase (e.g. cGMP PDE5) is desired. |