5-(2-SUBSTITUTED-5-HETEROCYCLYLSULPHONYLPYRID-3-YL)-DIHYDROPYRAZOLO[4,3-D]PYRIMIDIN-7-ONES AS PHOSPHODIESTERASE INHIBITORS

摘要

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.