Chemical compounds

1. A compound having a formula

wherein R 0 , independently, is selected from the group consisting of halo, C 1-6 alkyl, aryl, heteroaryl, C 3-8 cycloalkyl, C 3-8 heterocycloalkyl, C 3-8 cycloalkylQ, C(═O)R a , OC(═O)R a , C(═O)OR a , C 1-4 alkyleneNR a R b , C 1-4 alkyleneHet, C 1-4 alkyleneC(═O)OR a , C(═O)NR a SO 2 R c , C(═O)C 1-4 alkyleneHet, C(═O)NR a R b , C(═O)NR a R c , C(═O)NR a C 1-4 alkyleneoR b , C(═O)NR a C 1-4 alkyleneHet, OR a , OC 1-4 alkyleneC(═O)OR a , OC 1-4 alkyleneNR a R b , OC 1-4 alkyleneHet, OC 1-4 alkyleneOR a , OC 1-4 alkyleneNR a C(═O)OR b , NR a R b , NR a C 1-4 alkyleneNR a R b , NR a C(═O)R b , NR a C(═O)NR a R b , N(SO 2 C 1-4 alkyl) 2 , NR a (SO 2 C 1-4 alkyl), nitro, trifluoromethyl, trifluoromethoxy, cyano, SO 2 NR a R b , SO 2 R a , SOR a , SR a , and OSO 2 CF 3 ;

R 1 is selected from the group consisting of aryl optionally substituted with one or both of alkoxy and halo, an optionally substituted C 3-8 cycloalkyl ring, an optionally substituted C 3-8 heterocycloalkyl ring, an optionally substituted bicyclic ring

wherein the fused ring A is a 5- or 6-membered ring, saturated or partially or fully unsaturated, and contains carbon atoms and optionally one to three heteroatoms selected from oxygen, sulfur, and nitrogen, hydrogen, C 1-6 alkyl, arylC 1-3 alkyl, C 1-3 alkylenearyl, haloC 1-6 alkyl, C 1-4 alkyleneC(═O)OR a , C 1-4 alkyleneC(═O)NR a R b , C 3-8 cycloalkyl, C 3-8 cycloalkenyl, C 3-8 heterocycloalkenyl, C 1-4 alkyleneHet, C 1-4 alkyleneQR a , C 2-6 alkenyleneQR a , C 1-4 alkyleneQC 1-4 alkyleneQR a ,

and a spiro substituent having a structure

R 2 is selected from the group of hydrogen, C 1-6 alkyl, C 3-8 cycloalkyl, C 3-8 heterocycloalkyl, C 2-6 alkenyl, C 1-3 alkylenearyl, arylC 1-3 alkyl, C(═O)R a , aryl, heteroaryl, C(═O)R a , C(═O)NR a R b , C(═O)NR a R c , C(═S)NR a R b , C(═S)NR a R c , SO 2 R a , SO 2 NR a R b , S(═O)R a , S(═O)NR a R b , C(═O)NR a C 1-4 alkyleneOR a , C(═O)NR a C 1-4 alkyleneHet, C(═O)C 1-4 alkylenearyl, C(═O)C 1-4 alkyleneheteroaryl, C 1-4 alkylenearyl substituted with one or more of SO 2 NR a R b , NR a R b , C(═O)OR a , NR a SO 2 CF 3 , CN, NO 2 , C(═O)R a , OR a , C 1-4 alkyleneNR a R b , and OC 1-4 alkyleneNR a R b , C 1-4 alkyleneheteroaryl, C 1-4 alkyleneHet, C 1-4 alkyleneC(═O)C 1-4 alkylenearyl, C 1-4 alkyleneC(═O)C 1-4 alkyleneheteroaryl, C 1-4 alkyleneC(═O)Het, C 1-4 alkyleneC(═O)NR a R b , C 1-4 alkyleneOR a , C 1-4 alkyleneNR a C(═O)R a , C 1-4 alkyleneoC 1-4 alkyleneOR a , C 1-4 alkyleneNR a R b , C 1-4 alkyleneC(═O)OR a , and C 1-4 alkyleneaC 1-4 alkyleneC(═O)OR a ;

R 3 is selected from the group consisting of C(═O)R b , C(═O)OR b , C(═O)NR a R b , C(═O)NR a R c , C(═S)NR a R b , C(═S)NR a R c , C(═O)Het, C(═O)NR a C 1-4 alkyleneOR a , C(═O)NR a C 1-4 alkyleneHet, C(═O)C 1-4 alkylenearyl, C(═O)C 1-4 alkyleneheteroaryl, C(═O)NR a C 1-4 alkylenearyl, C(═O)NR a C 1-4 alkyleneC 3-8 cycloalkyl, C(═O)NR b SO 2 R c , C(═O)NR a C 1-4 alkyleneOC 1-6 alkyl, C(═O)NR a C 1-4 alkyleneheteroaryl, NR a R c , NR a C(═O)R b , NR a C(═O)NR a R c , NR a (SO 2 C 1-4 alkyl), N(SO 2 C 1-4 alkyl) 2 , OR a , NR a C(═O)C 1-4 alkyleneN(R b ) 2 , NR a C(═O)C 1-4 alkyleneC(═O)OR a , NR a (C═O)C 1-3 alkylenearyl, NR a C(═O)C 1-3 alkyleneC 3-8 heterocycloalkyl, NR a C(═O)C 1-3 alkyleneHet, and C(═O)NR a SO 2 R b ;

R 4 is selected from the group consisting of hydrogen, C 1-6 alkyl, aryl, heteroaryl, arylC 1-3 alkyl, C 1-3 alkylenearyl, C 1-3 alkyleneHet, C 3-8 cycloalkyl, and C 3-8 heterocycloalkyl;

X is selected from the group consisting of C(═O), (CH 2 ) t C(═O), C(═O)C≡C, C(═S), SO, SO 2 , SO 2 C(R a )═CR a , CR a ═CR a , C(═O)NR a , and C(═N—OR a );

Y is R a ;

R a is selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-6 cycloalkyl, phenyl, phenylC 1-3 alkyl, and C 1-3 alkylenephenyl;

R b is selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-8 cycloalkyl, C 1-3 alkyleneN(R a ) 2 , aryl, arylC 1-3 alkyl, C 1-3 alkylenearyl, and heteroaryl;

R c is selected from the group consisting of hydrogen, C 1-6 alkyl, aryl, heteroaryl, arylC 1-3 alkyl, heteroarylC 1-3 alkyl, C 1-3 alkyleneN(R a )2, C 1-6 alkylenearyl, C 1-6 alkyleneHet, haloC 1-6 alkyl, C 3-8 cycloalkyl, C 3-8 heterocycloalkyl, Het, C 1-3 alkyleneheteroaryl, C 1-6 alkyleneC(═O)OR a , and C 1-3 alkyleneC 3-8 heterocycloalkyl;

or R a and R c are taken together to form a 5- or 6-membered ring, optionally containing at least one heteroatom;

Q is O, S, or NR h ;

B is O, S, or NR h ;

C is O, S, or NR a ;

D is CR a , or N;

E is CR a , C(R a ) 2 , or NR h ; and

R h is null or is selected from the group consisting of hydrogen, C 1-6 alkyl, aryl, heteroaryl, arylC 1-3 alkyl, heteroarylC 1-3 alkyl, C 1-3 alkylenearyl, and C 1-3 alkyleneheteroaryl;

Het represents a 5- or 6-membered heterocyclic ring, saturated or partially or fully unsaturated, containing at least one heteroatom selected from the group consisting of oxygen, nitrogen, and sulfur, and optionally substituted with C 1-4 alkyl or C(═O)OR a ;

n is 1;

q is 0, 1, 2, 3, or 4;

t is 1, 2, 3, or 4;

or a pharmaceutically acceptable salt or solvate thereof.

2. The compound of claim 1 represented by the formula

or a pharmaceutically acceptable salt or solvate thereof.

3. The compound of claim 1 wherein q is 0, or R 0 is selected from the group consisting of aryl, Het, OR a , C(═O)OR a , C 1-4 alkyleneNR a R b , OC(═O)R a , C(═O)R a , NR a R b , C 3-8 cycloalkyl, C 3-8 cycloalkylQ, C(═O)NR a R b , and C(═O)NR a R c .

4. The compound of claim 1 wherein R 1 is selected from the group consisting of optionally substituted aryl, C 1-4 alkyleneQR a , C 1-4 alkyleneQC 1-4 alkyleneQR a , C 3-8 cycloalkyl, C 3-8 cycloalkenyl, C 1-6 alkyl,

5. The compound of claim 1 wherein R 1 is the optionally substituted bicyclic ring system

6. The compound of claim 5 wherein R 1 is

and wherein p is an integer 1 or 2, and G, independently, are C(R a ) 2 , O, S, or NR a .

7. The compound of claim 1 wherein R 1 is selected from the group consisting of

8. The compound of claim 1 wherein R 2 is selected from the group consisting of hydrogen, aryl, heteroaryl, OR a , NR a R b , NR a R c , C 1-4 alkyleneHet, C 1-4 alkyleneheteroaryl, C 1-4 alkylenearyl, C 1-4 alkyleneC(═O)C 1-4 alkylenearyl, C 1-4 alkyleneC(═O)OR a , C 1-4 alkyleneC(═O)NR a R b , C 1-4 alkyleneC(═O)NR a R c , C 1-4 alkyleneC(═O)Het, C 1-4 alkyleneNR a R b , C 1-4 alkyleneNR a R c , C 1-4 alkyleneNR a C(═O)R a , and C 1-4 alkyleneOC 1-4 alkyleneOR a .

9. The compound of claim 8 wherein R 2 is selected from the group consisting of hydrogen; C 1-4 alkyleneheteroaryl, wherein the heteroaryl group is selected from the group consisting of benzimidazole, a triazole, and irnidazole; C 1-4 alkyleneHet, wherein Het is selected from the group consisting of piperazine, morpholine, pyrrolidine, pyrrolidone, tetrahydrofuran, piperidine,

C 1-4 alkyleneC 6 H 5 , optionally substituted with one to three groups selected from the group consisting of C(═O)OR a , NR a R b , NR a SO 2 CF 3 , SO 2 NR a R b , CN, OR a , C(═O)R a , C 1-4 alkyleneNR a R b , nitro, OC 1-4 alkylenearyl, and OC 1-4 alkyleneNR a R b ; C 1-4 alkyleneC(═O)benzyl; C 1-4 alkyleneC(═O)OR a ; C 1-4 alkyleneC(═O)NR a R b ; C 1-4 alkyleneC(═O)NR a R c ; C 1-4 alkyleneHet; NR a R b ; OH; OC 1-4 alkyl; C 6 H 5 ; C 1-4 alkyleneNR a R b ; C 1-4 alkyleneOR a ; C 1-4 alkyleneNHC(═O)R a ; and C 1-4 alkyleneOC 1-4 alkyleneOR a .

10. The compound of claim 8 wherein R 2 is selected from the group consisting of C 1-6 alkyl, C(═O)OR a , C(═O)R a , hydrogen, C(═O)NR a C 1-4 alkyleneHet, C(═O)NR a R c , aryl, and heteroaryl.

11. The compound of claim 1 wherein R 3 is selected from the group consisting of C(═O)OR b , C(═O)R b , C(═O)NR a C 1-4 alkyleneOC 1-6 alkyl, C(═O)NR a C 1-4 alkyleneC 3-8 cycloalkyl, C(═O)Het,

C(═O)NR a C 1-4 alkyleneheteroaryl, C(═O)NR a C 1-4 alkylenearyl, C(═O)NR a C 1-4 alkyleneHet, C(═O)NR a R c , and C(═S)NR a R c .

12. The compound of claim 1 wherein R 4 is selected from the group consisting of hydrogen, C 1-6 alkyl, aryl, and heteroaryl.

13. The compound of claim 1 wherein X is selected from the group consisting of C(═O), (CH 2 ) t C═O, C(═S) and C(═N—OR a ).

14. The compound of claim 1 wherein q is 0, or R 0 is selected from the group consisting of halo, methyl, trifluoromethyl, and trifluoromethyl; R 1 is selected from the group consisting of

R 2 is selected from the group consisting of hydrogen, C 1-6 alkyl, C(═O)NR a R c , and C 1-4 alkyleneHet; R 3 is selected from the group consisting of C(═O)OC 2 H 5 , C(═O)OCH 3 , C(═O)NHCH 2 C 6 H 5 , C(═O)NH(CH 2 ) 2 C 6 H 5 , C(═O)NHC 6 H 5 , C(═O)NH 2 , C(═O)N(CH3) 2 , C(═S)N(CH 3 ) 2 , C(═O)NH(CH 2 ) 2 CH 3 , C(═O)N(CH 2 ) 3 CH 3 , C(═O)NHCH 3 , C(═O)NHCH(CH 3 ) 2 , C(═O)NH(CH 2 ) 3 OCH 3 ,

and R 4 is hydrogen or C 1-6 alkyl.

15. The compound of claim 1 wherein q is 0, R 2 is hydrogen, and R 4 is hydrogen or methyl.

16. A compound selected from the group consisting of

or a pharmaceutically acceptable salt or solvate thereof.

17. A pharmaceutical composition comprising a compound of claim 1 , together with a pharmaceutically acceptable diluent or carrier.

18. A method of treating a male animal for male erectile dysfunction comprising administering to said male animal an effective amount of a pharmaceutical composition comprising a compound of claim 1 , together with a pharmaceutically acceptable diluent or carrier.

19. The method of claim 18 wherein the treatment is an oral treatment.

20. A method for the prophylactic treatment of male erectile dysfunction comprising administration of an effective dose of a compound of claim 1 , or a pharmaceutically acceptable salt or solvate thereof, to a male animal.

21. A compound having a formula

wherein R 0 , independently, is selected from the group consisting of halo, C 1-6 alkyl, aryl, heteroaryl, C 3-8 cycloalkyl, C 3-8 heterocycloalkyl, C 3-8 cycloalkylQ, C(═O)R a , OC(═O)R a , C(═O)OR a , C 1-4 alkyleneNR a R b , C 1-4 alkyleneHet, C 1-4 alkyleneC(═O)OR a , C(═O)NR a SO 2 R c , C(═O)C 1-4 alkyleneHet, C(═O)NR a R b , C(═O)NR a R c , C(═O)NR a C 1-4 alkyleneOR b , C(═O)NR a C 1-4 alkyleneHet, OR a , OC 1-4 alkyleneC(═O)OR a , OC 1-4 alkyleneNR a R b , OC 1-4 alkyleneHet, OC 1-4 alkyleneOR a , OC 1-4 alkyleneNR a C(═O)OR b , NR a R b , NR a C 1-4 alkyleneNR a R b , NR a C(═O)R b , NR a C(═O)NR a R b , N(SO 2 C 1-4 alkyl) 2 , NR a (SO 2 C 1-4 alkyl), nitro, trifluoromethyl, trifluoromethoxy, cyano, SO 2 NR a R b , SO 2 R a , SOR a , SR a , and OSO 2 CF 3 ;

R 1 is selected from the group consisting of aryl substituted with one or both of halo and methoxy, optionally substituted heteroaryl, an optionally substituted C 3-8 cycloalkyl ring, an optionally substituted C 3-8 heterocycloalkyl ring, an optionally substituted bicyclic ring

wherein the fused ring A is a 5- or 6-membered ring, saturated or partially or fully unsaturated, and contains carbon atoms and optionally one to three heteroatoms selected from oxygen, sulfur, and nitrogen, C 1-4 alkyleneC(═O)OR a , C 1-4 alkyleneC(═O)NR a R b , C 3-8 cycloalkyl, C 3-8 cycloalkenyl, C 3-8 heterocycloalkenyl, C 1-4 alkyleneHet, C 1-4 alkyleneQR a , C 2-6 alkenyleneQR a , C 1-4 alkyleneQC 1-4 alkyleneQR a ,

and a spiro substituent having a structure

R 2 is selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-8 cycloalkyl, C 3-8 heterocycloalkyl, C 2-6 alkenyl, C 1-3 alkylenearyl, arylC 1-3 alkyl, C(═O)R a , aryl, heteroaryl, C(═O)R a , C(═O)NR a R b , C(═O)NR a R c , C(═S)NR a R b , C(═S)NR a R c , SO 2 R a , SO 2 NR a R b , S(═O)R a , S(═O)NR a R b , C(═O)NR a C 1-4 alkyleneOR a , C(═O)NR a C 1-4 alkyleneHet, C(═O)C 1-4 alkylenearyl, C(═O)C 1-4 alkyleneheteroaryl, C 1-4 alkylenearyl substituted with one or more of SO 2 NR a R b , NR a R b , C(═O)OR a , NR a SO 2 CF 3 , CN, NO 2 , C(═O)R a , OR a , C 1-4 alkyleneNR a R b , and OC 1-4 alkyleneNR a R b , C 1-4 alkyleneheteroaryl, C 1-4 alkyleneHet, C 1-4 alkyleneC(═O)C 1-4 alkylenearyl, C 1-4 alkyleneC(═O)C 1-4 alkyleneheteroaryl, C 1-4 alkyleneC(═O)Het, C 1-4 alkyleneC(═O)NR a R b , C 1-4 alkyleneOR a , C 1-4 alkyleneNR a C(═O)R a , C 1-4 alkyleneOC 1-4 alkyleneOR a , C 1-4 alkyleneNR a R b , C 1-4 alkyleneC(═O)OR a , and C 1-4 alkyleneOC 1-4 alkyleneC(═O)OR a ;

R 3 is selected from the group consisting of C(═O)R b , C(═O)NR a R b , C(═O)NR a R c , C(═S)NR a R b , C(═S)NR a R c , C(═O)Het, C(═O)NR a C 1-4 alkyleneOR a , C(═O)NR a C 1-4 alkyleneHet, C(═O)C 1-4 alkylenearyl, C(═O)C 1-4 alkyleneheteroaryl, C(═O)NR a C 1-4 alkylenearyl, C(═O)NR a C 1-4 alkyleneC 3-8 cycloalkyl, C(═O)NR b SO 2 R c , C(═O)NR a C 1-4 alkyleneOC 1-6 alkyl, C(═O)NR a C 1-4 alkyleneheteroaryl, NR a R c , NR a C(═O)R b , NR a C(═O)NR a R c , NR a (SO 2 C 1-4 alkyl), N(SO 2 C 1-4 alkyl) 2 , OR a , NR a C(═O)C 1-4 alkyleneN(R b ) 2 , NR a C(═O)C 1-4 alkyleneC(═O)OR a , NR a (C═O)C 1-3 alkylenearyl, NR a C(═O)C 1-3 alkyleneC 3-8 heterocycloalkyl, NR a C(═O)C 1-3 alkyleneHet, and C(═O)NR a SO 2 R b ;

R 4 is selected from the group consisting of hydrogen, C 1-6 alkyl, aryl, heteroaryl, arylC 1-3 alkyl, C 1-3 alkylenearyl, C 1-3 alkyleneHet, C 3-8 cycloalkyl, and C 3-8 heterocycloalkyl;

R a is selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-6 cycloalkyl, aryl, arylC 1-3 alkyl, C 1-3 alkylenearyl, heteroaryl, heteroarylC 1-3 alkyl, and C 1-3 alkyleneheteroaryl;

R b is selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-8 cycloalkyl, C 1-3 alkyleneN(R a ) 2 , aryl, arylC 1-3 alkyl, C 1-3 alkylenearyl, and heteroaryl;

R c is selected from the group consisting of hydrogen, C 1-6 alkyl, aryl, heteroaryl, arylC 1-3 alkyl, heteroarylC 1-3 alkyl, C 1-3 alkyleneN(R a ) 2 , C 1-6 alkylenearyl, C 1-6 alkyleneHet, haloC 1-6 alkyl, C 3-8 cycloalkyl, C 3-8 heterocycloalkyl, Het, C 1-3 alkyleneheteroaryl, C 1-6 alkyleneC(═O)OR a , and C 1-3 alkyleneC 3-8 heterocycloalkyl;

or R a and R c are taken together to form a 5- or 6-membered ring, optionally containing at least one heteroatom;

Q is O, S, or NR h ;

B is O, S, or NR h ;

C is O, S, or NR a ;

D is CR a or N;

E is CR a , C(R a )2, or NR h ; and

R h is null or is selected from the group consisting of hydrogen, C 1-6 alkyl, aryl, heteroaryl, arylC 1-3 alkyl, heteroarylC 1-3 alkyl, C 1-3 alkylenearyl, and C 1-3 alkyleneheteroaryl;

Het represents a 5- or 6-membered heterocyclic ring, saturated or partially or fully unsaturated, containing at least one heteroatom selected from the group consisting of oxygen, nitrogen, and sulfur, and optionally substituted with C 1-4 alkyl or C(═O)OR a ;

q is 0, 1, 2, 3, or 4;

or a pharmaceutically acceptable salt or solvate thereof.

22. The compound of claim 21 represented by the formula

or a pharmaceutically acceptable salt or hydrate thereof.

23. The compound of claim 21 wherein q is 0, or R 0 is selected from the group consisting of aryl, Het, OR a , C(═O)OR a , C 1-4 alkyleneNR a R b , OC(═O)R a , C(═O)R a , NR a R b , C 3-8 cycloalkyl, C 3-8 cycloalkylQ, C(═O)NR a R b , and C(═O)NR a R c .

24. The compound of claim 21 wherein R 1 is selected from the group consisting of aryl substituted with one or both of chloro and methoxy, optionally substituted heteroaryl, C 1-4 alkyleneQR a , C 1-4 alkyleneQC 1-4 alkyleneQR a , C 3-8 cycloalkyl, C 3-8 cycloalkenyl,

25. The compound of claim 21 wherein R 1 is the optionally substituted bicyclic ring system

26. The compound of claim 25 wherein R 1 is

and wherein p is an integer 1 or 2, and G, independently, are C(R a ) 2 , O, S, or NR a .

27. The compound of claim 21 wherein R 1 is selected from the group consisting of

28. The compound of claim 21 wherein R 2 is selected from the group consisting of aryl, hydrogen, heteroaryl, OR a , NR a R b , NR a R c , C 1-4 alkyleneHet, C 1-4 alkyleneheteroaryl, C 1-4 alkylenearyl, C 1-4 alkyleneC(═O)C 1-4 alkylenearyl, C 1-4 alkyleneC(═O)OR a , C 1-4 alkyleneC(═O)NR a R b , C 1-4 alkyleneC(═O)NR a R c , C 1-4 alkyleneC(═O)Het, C 1-4 alkyleneNR a R b , C 1-4 alkyleneNR a R c , C 1-4 alkyleneNR a C(═O)R a , and C 1-4 alkyleneOC 1-4 alkyleneOR a .

29. The compound of claim 21 wherein R 2 is selected from the group consisting of hydrogen; C 1-4 alkyleneheteroaryl, wherein the heteroaryl group is selected from the group consisting of benzimidazole, a triazole, and imidazole; C 1-4 alkyleneHet, wherein Het is selected from the group consisting of piperazine, morpholine, pyrrolidine, pyrrolidone, tetrahydrofuran, piperidine,

C 1-4 alkyleneC 6 H 5 , optionally substituted with one to three groups selected from the group consisting of C(═O)OR a , NR a R b , NR a SO 2 CF 3 , SO 2 NR a R b , CN, OR a , C(═O)R a , C 1-4 alkyleneNR a R b , nitro, OC 1-4 alkylenearyl, and OC 1-4 alkyleneNRaRb; C 1-4 alkyleneC(═O)benzyl; C 1-4 alkyleneC(═O)OR a ; C 1-4 alkyleneC(═O)NR a R b ; C 1-4 alkyleneC(═O)NR a R c ; C 1-4 alkyleneHet; NR a R b ; OH; OC 1-4 alkyl; C 6 H 5 ; C 1-4 alkyleneNR a R b ; C 1-4 alkyleneOR a ; C 1-4 alkyleneNHC(═O)R a ; and C 1-4 alkyleneOC 1-4 alkyleneOR a .

30. The compound of claim 21 wherein R 2 is selected from the group consisting of C 1-6 alkyl, C(═O)OR a , C(═O)R a , hydrogen, C(═O)NR a C 1-4 alkyleneHet, C(═O)NR a R c , aryl, and heteroaryl.

31. The compound of claim 21 wherein R 3 is selected from the group consisting of C(═O)R b , C(═O)NR a C 1-4 alkyleneOC 1-6 alkyl, C(═O)NR a C 1-4 alkyleneC 3-8 cycloalkyl, C(═O)Het,

C(═O)NR a C 1-4 alkyleneheteroaryl, C(═O)NR a C 1-4 alkylenearyl, C(═O)NR a C 1-4 alkyleneHet, C(═O)NR a R c , and C(═S)NR a R c .

32. The compound of claim 21 wherein R 4 selected from the group consisting of hydrogen, C 1-6 alkyl, aryl, and heteroaryl.

33. The compound of claim 21 wherein q is 0, or R 0 is selected from the group consisting of halo, methyl, trifluoromethyl, and trifluoromethyl; R 1 is selected from the group consisting of

R 2 is selected from the group consisting of hydrogen, C 1-6 alkyl, C(═O)NR a R c , and C 1-4 alyleneHet; R 3 is selected from the group consisting of C(═O)NHCH 2 C 6 H 5 , C(═O)NH(CH 2 ) 2 C 6 H 5 , C(═O)NHC 6 H 5 , C(═O)NH 2 , C(═O)N(CH 3 ) 2 , C(═S)N(CH 3 ) 2 , C(═O)NH(CH 2 ) 2 CH 3 , C(═O)N(CH 2 ) 3 CH 3 , C(═O)NHCH 3 , C(═O)NHCH(CH 3 ) 2 , C(═O)NH(CH 2 ) 3 OCH 3 ,

and R 4 is hydrogen and C 1-6 alkyl.

34. The compound of claim 21 wherein q is 0, R 2 is hydrogen, and R 4 is hydrogen or methyl.

35. A compound selected from the group consisting of

or a pharmaceutically acceptable salt or solvate thereof.

36. A pharmaceutical composition comprising a compound of claim 21 , together with a pharmaceutically acceptable diluent or carrier.

37. A method of treating a male animal for male erectile dysfunction comprising administering to said male animal an effective amount of a pharmaceutical composition comprising a compound of claim 21 , together with a pharmaceutically acceptable diluent or carrier.

38. The method of claim 37 wherein the treatment is an oral treatment.

39. A method for prophylactic treatment of male erectile dysfunction comprising administration of an effective dose of a compound of claim 21 , or a pharmaceutically acceptable salt or solvate thereof, to a male animal.