Piperazines as antimalarial agents

1. A compound of the formula I:

wherein

X is CH or N;

R 1 represents —NO 2 , —N(CH 3 ) 2 , or —NCH 3 (CH 2 CH 2 OH); and

R 2 represents hydrogen, methyl, ethyl, n-propyl, isopropyl, tert-butyl, cyano, halogen, methoxy, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, methylsulfonyl, acetyl, or acetylamino; or

X is CH, R 1 is hydrogen, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, methylsulfonyl, acetylamino, or methoxycarbonyl; or

X is CH, R 1 is cyano, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, trifluoromethoxy, methylsulfonyl, or acetylamino; or

X is CH, R 1 is chloro, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, difluoromethoxy, methylsulfonyl, or acetylamino; or

X is CH, R 1 is methoxy or isopropoxy, and R 2 is trifluoromethyl; or

X is CH, R 1 is methylsulfonyl or ethylsulfonyl, and R 2 is trifluoromethyl, ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, or difluoromethoxy;

or a salt of such a compound.

2. The compound according to claim 1 , wherein

X is CH or N;

R 1 represents —NO 2 , —N(CH 3 ) 2 , or —NCH 3 (CH 2 CH 2 OH); and

R 2 represents hydrogen, methyl, ethyl, n-propyl, isopropyl, tert-butyl, cyano, halogen, methoxy, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, methylsulfonyl, acetyl, or acetylamino; or

X is CH, R 1 is hydrogen, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, methylsulfonyl, acetylamino, or methoxycarbonyl; or

X is CH, R 1 is cyano, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, trifluoromethoxy, methylsulfonyl, or acetylamino; or

X is CH, R 1 is chloro, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, difluoromethoxy, methylsulfonyl, or acetylamino; or

X is CH, R 1 is methoxy or isopropoxy, and R 2 is trifluoromethyl;

or a salt of such a compound.

3. The compound according to claim 1 , wherein

X is CH or N;

R 1 represents —NO 2 , —N(CH 3 ) 2 , or —NCH 3 (CH 2 CH 2 OH); and

R 2 represents ethyl, isopropyl, tert-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, methylsulfonyl, or acetylamino; or

X is CH, R 1 is hydrogen, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, methylsulfonyl, acetylamino, or methoxycarbonyl; or

X is CH, R 1 is cyano, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, trifluoromethoxy, methylsulfonyl, or acetylamino; or

X is CH, R 1 is chloro, and R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, difluoromethoxy, methylsulfonyl, or acetylamino; or

X is CH, R 1 is methoxy or isopropoxy, and R 2 is trifluoromethyl;

or a salt of such a compound.

4. The compound according to claim 1 , wherein

R 1 represents —NO 2 , —N(CH 3 ) 2 , or —NCH 3 (CH 2 CH 2 OH); and

R 2 represents hydrogen, methyl, ethyl, n-propyl, isopropyl, tert-butyl, cyano, halogen, methoxy, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, methylsulfonyl, acetyl, or acetylamino;

or a salt of such a compound.

5. The compound according to claim 1 , wherein

R 1 represents —NO 2 , —N(CH 3 ) 2 , or —NCH 3 (CH 2 CH 2 OH); and

R 2 represents ethyl, isopropyl, tert-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, methylsulfonyl, or acetylamino;

or a salt of such a compound.

6. The compound according to claim 4 , wherein X is CH, or a salt of such a compound.

7. The compound according to claim 4 , wherein X is N, or a salt of such a compound.

8. The A compound according to claim 4 , wherein R 1 represents —NO 2 , or a salt of such a compound.

9. The compound according to claim 4 , wherein R 1 represents —N(CH 3 ) 2 , or a salt of such a compound.

10. The compound according to claim 4 , wherein R 1 represents —NCH 3 (CH 2 CH 2 OH), or a salt of such a compound.

11. The compound according to claim 4 , wherein R 2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, or isopropoxy, or a salt of such a compound.

12. The compound according to claim 11 , wherein R 2 is isopropoxy, or a salt of such a compound.

13. The compound according to claim 4 , wherein R 2 is trifluoromethyl, difluoromethoxy, methylsulfonyl, or acetylamino, or a salt of such a compound.

14. The compound according to claim 4 , wherein R 2 is methoxy, or a salt of such a compound.

15. The compound according to claim 4 , wherein R 2 is hydrogen, methyl, n-propyl, cyano, halogen, or acetyl, or a salt of such a compound.

16. The compound according to claim 1 , selected from the group consisting of:

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-trifluoromethyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(6-trifluoromethyl-pyridin-3-yl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(6-methoxy-pyridin-3-yl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(6-ethoxy-pyridin-3-yl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-ethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-methanesulfonyl-phenyl)-acrylamide,

(S)-3-(4-Acetylamino-phenyl)-N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-propoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-isopropoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-ethyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-difluoromethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-isopropyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-trifluoromethyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(6-trifluoromethyl-pyridin-3-yl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(6-methoxy-pyridin-3-yl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(6-ethoxy-pyridin-3-yl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-ethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-methanesulfonyl-phenyl)-acrylamide,

(S)-3-(4-Acetylamino-phenyl)-N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-propoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-isopropoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-ethyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-difluoromethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-isopropyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-tert-butyl-phenyl)-acrylamide, and

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-nitro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-trifluoromethyl-phenyl)-acrylamide,

or salts of these compounds.

17. The compound according to claim 1 , selected from the group consisting of:

(S)—N-[4-(4-Acetyl-piperazin-1-yl)benzyl]-N-{1-(4-(4-(dimethylamino)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl}cinnamamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)benzyl]-N-{1-[4-(4-(dimethylamino)benzyl)piperazin-1-yl]-1-oxo-3-phenylpropan-2-yl}-3-(p-tolyl)acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)benzyl]-N-{1-(4-(4-(dimethylamino)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl}-3-(4-propylphenyl)acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)benzyl]-N-{1-(4-(4-(dimethylamino)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl}-3-(4-methoxyphenyl)acrylamide,

(S)-3-(4-Acetyl-phenyl)-N-[4-(4-acetyl-piperazin-1-yl)benzyl]-N-{1-(4-(4-(dimethylamino)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl}acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)benzyl]-3-(4-cyanophenyl)-N-{1-(4-(4-(dimethylamino)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl}acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)benzyl]-N-{1-(4-(4-(dimethylamino)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl}-3-(4-fluorophenyl)acrylamide, and

(S)—N-[4-(4-Acetyl-piperazin-1-yl)benzyl]-3-(4-chlorophenyl)-N-{1-(4-(4-(dimethylamino)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl}acrylamide, or salts of these compounds.

18. The compound according to claim 1 , selected from the group consisting of:

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-3-(4-ethyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-3-(4-tert-butyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-3-(4-ethoxy-phenyl)-acrylamide,

(S)-4-(2-{[4-(4-Acetyl-piperazin-1-yl)-benzyl]-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-carbamoyl}-vinyl)-benzoic acid methyl ester,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-3-(4-methanesulfonyl-phenyl)-acrylamide,

(S)-3-(4-Acetylamino-phenyl)-N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-3-(4-propoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-3-(4-isopropoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-benzyl-piperazin-1-yl)-2-oxo-ethyl]-3-(4-isopropyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-trifluoromethyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-ethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-methanesulfonyl-phenyl)-acrylamide,

(S)-3-(4-Acetylamino-phenyl)-N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-propoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-isopropoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-ethyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-difluoromethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-isopropyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-trifluoromethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-ethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-methanesulfonyl-phenyl)-acrylamide,

(S)-3-(4-Acetylamino-phenyl)-N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-propoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-isopropoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-ethyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-difluoromethoxy-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-isopropyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-methoxy-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-trifluoromethyl-phenyl)-acrylamide, and

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-isopropoxy-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-trifluoromethyl-phenyl)-acrylamide, or salts of these compounds.

19. The compound according to claim 1 , selected from the group consisting of:

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-(methylsulfonyl)-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-isopropoxyphenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-(methylsulfonyl)-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-(methylsulfonyl)-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-propoxyphenyl)-acrylamide,

(S)—N-(4-(4-acetylpiperazin-1-yl)benzyl)-N-(1-(4-(4-(methylsulfonyl)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl)-3-(4-(trifluoromethyl)phenyl)acrylamide,

(S)—N-[4-(4-Acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-(ethylsulfonyl)-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-propoxyphenyl)-acrylamide, and

(S)—N-(4-(4-acetylpiperazin-1-yl)benzyl)-N-(1-(4-(4-(ethylsulfonyl)benzyl)piperazin-1-yl)-1-oxo-3-phenylpropan-2-yl)-3-(4-(trifluoromethyl)phenyl)acrylamide,

or salts of these compounds.

20. A pharmaceutical composition comprising a compound according to claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier material.

21. A method for the treatment of malaria comprising administering to a subject a pharmaceutically active amount of the compound according to claim 1 , or a pharmaceutically acceptable salt thereof.

22. A compound according to claim 1 , which is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a salt thereof.

23. A compound according to claim 1 , which is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-propoxy-phenyl)-acrylamide, or a salt thereof.

24. A compound according to claim 1 , which is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a salt thereof.

25. A compound according to claim 1 , which is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-(methylsulfonyl)-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a salt thereof.

26. A compound according to claim 1 , which is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-tert-butyl-phenyl)-acrylamide, or a salt thereof.

27. The pharmaceutical composition according to claim 20 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

28. The pharmaceutical composition according to claim 20 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-propoxy-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

29. The pharmaceutical composition according to claim 20 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

30. The pharmaceutical composition according to claim 20 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-(methylsulfonyl)-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

31. The pharmaceutical composition according to claim 20 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-tert-butyl-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

32. The method according to claim 21 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-dimethylamino-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

33. The method according to claim 21 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-propoxy-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

34. The method according to claim 21 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-cyano-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

35. The method according to claim 21 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-{1-benzyl-2-[4-(4-(methylsulfonyl)-benzyl)-piperazin-1-yl]-2-oxo-ethyl}-3-(4-tert-butyl-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.

36. The method according to claim 21 , wherein the compound is (S)—N-[4-(4-acetyl-piperazin-1-yl)-benzyl]-N-[1-benzyl-2-(4-{4-[(2-hydroxy-ethyl)-methyl-amino]-benzyl}-piperazin-1-yl)-2-oxo-ethyl]-3-(4-tert-butyl-phenyl)-acrylamide, or a pharmaceutically acceptable salt thereof.