There is provided compounds of formula (I) wherein R?1, R2, R3, R4¿ and X have meanings given in the description, which are useful in the curative and prophylactic treatment of a medical condition for which inhibition of a cyclic guanosine 3',5'-monophosphate phosphodiesterase (e.g. cGMP PDE5) is desired.
提供了式(I)的化合物,其中R?1,R2,R3,R4¿和X具有在说明中给出的含义,这些化合物在治疗和预防需要抑制环
磷酸鸟苷3',5'-单
磷酸磷酸二酯酶(例如cGMP PDE5)的医疗状况中是有用的。