abstract |
There is provided compounds of formula IA and of formula IB,n nwherein R 1 , R 2 , R 3 , R 4 and A have meanings given in the description,nwhich are useful in the curative and prophylactic treatment of a medicalncondition for which inhibition of a cyclic guanosine 3',5'-monophosphatenphosphodiesterase (e.g. cGMP PDE5) is desired. |