Method for producing pyrazolopyrimidinone intermediates that inhibit type 5 cyclic guanosine 3 ', 5'-monophosphate phosphodiesterase (cGMPPDE5) for the treatment of sexual dysfunction

摘要

Compounds of formulae (IA) and (IB) or pharmaceutically or veterinarily acceptable salts thereof, or pharmaceutically or veterinarily acceptable solvates of either entity, wherein R1 is C1 to C3 alkyl substituted with C3 to C6 cycloalkyl, CONR5R6 or a N-linked heterocyclic group; (CH2)nHet or (CH2)nAr; R2 is C1 to C6 alkyl; R3 is C1 to C6 alkyl optionally substituted with C1 to C4 alkoxy; R4 is SO2NR7R8; R5 and R6 are each independently selected from H and C1 to C4 alkyl optionally substituted with C1 to C4 alkoxy, or, together with the nitrogen atom to which they are attached, form a 5- or 6-membered heterocyclic group; R7 and R8, together with the nitrogen atom to which they are attached, form a 4-R10-piperazinyl group; R10 is H or C1 to C4 alkyl optionally substituted with OH, C1 to C4 alkoxy or CONH2; H is an optionally substituted C-linked 5- or 6-membered heterocyclic group; Ar is optionally substituted phenyl; and n is 0 or 1; are potent and selective cGMP PDE5 inhibitors useful in the treatment of, inter alia, male erectile dysfunction and female sexual dysfunction.