A process for the preparation of Compounds of the formula (1): ##STR00001## wherein R.sup.1, R.sup.2, R.sup.4 and R.sup.13 are as defined or a pharmaceutically or veterinarily acceptable salt or polymorph thereof, or a pharmaceutically or veterinarily acceptable solvate or pro-drug thereof: are potent and selective inhibitors of type 5 cyclic guanosine 3',5'-monophosphate phosphodiestbrase (cGMP PDE5) and have utility in the treatment of, inter alia, male erectile dysfunction (MED) and female sexual dysfunction (FSD).
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. patent application No. 09/685,080 filed on Oct. 6, 2000, now U.S. Pat. No. 6,677,335, which was filed claiming priority from U.S. provisional application 60/168,059 filed Nov. 30, 1999 and from U.S. provisional application 60/231,122 filed Sep. 8, 2000. The entire text of each of the preceding documents is herein incorporated by reference.
Priority Data
Oct 11, 1999 [GB] 9924063.2 Jul 28, 2000 [GB] 0018656.9
