8-Quinolinxanthine and 8-isoquinolinxanthine derivatives as PDE 5 inhibitors

1 2 3 4 5 676 7 6 7 6 7 A compound of formula (I) Ris hydrogen or alkyl optionally substituted by hydroxy, alkoxy, or alkylthio, Ris hydrogen, alkyl, hydroxyalkyl, alkylcarbonyloxyalkyl, alkoxyalkyl, alkylthioalkyl, alkenyl, cycloalkylalkyl, heterocyclylalkyl, aralkyl in which the aryl ring thereof is optionally fused to a 5-membered heterocyclic group or is optionally substituted by one or more substituents selected from alkoxy, amino, alkylamino, dialkylamino, acylamino, halogen, hydroxy, aminosulfonyl, alkylaminosulfonyl, dialkylaminosulfonyl, alkylsulfonylamino or dialkylaminosulfonylamino, Ris hydrogen or alkyl optionally substituted by hydroxy, alkoxy, or alkylthio, Ris hydrogen or alkyl, Ris a quinolinyl, isoquinolinyl or oxodihydroisoquinolinyl group optionally fused to a 5-membered heterocyclic group and optionally substituted by one or more substituents selected from halogen, cyano, hydroxy, alkyl, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkoxy, alkylthio, alkenyl, alkoxycarbonyl, alkynyl, carboxyl, acyl, a group of formula -N(R)R, aryl optionally substituted by one or more substituents selected from halogen or alkoxy, or heteroaryl having 5 or 6 ring atoms attached through a ring carbon atom to the indicated carbon atom, and Rand Rare each independently hydrogen or alkyl optionally substituted by hydroxy or alkoxy or one of Rand Ris hydrogen and the other is acyl, or Rand Rtogether with the nitrogen atom to which they are attached denote a 5- or 6-membered heterocyclyl group.