December 30, 2003

There is provided compounds of formula IA and of formula IB, ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and A 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.

13

December 30, 2003

09/426,552

October 22, 1999

514/262.1   514/234.2 544/118 544/262 546/293 548/364.1 548/372.5

C07D   401/12   (20060101)   C07D   401/00   (20060101)   C07D   487/04   (20060101)   C07D   487/00   (20060101)   C07D   231/14   (20060101)   C07D   231/00   (20060101)  

Oct 23, 1998 [GB] 9823101

540/575   546/247   546/193   546/293   514/218   514/234.2   514/262.1   544/118   544/256   544/262   548/364.1   548/372.5