N-(1-arylpyrazol-4l) sulfonamides and their use as parasiticides

1. A compound of formula (I) or a pharmaceutically, veterinarily or agriculturally acceptable salt thereof,

wherein:

R 1 is phenyl optionally substituted by one or more groups independently selected from the group consisting of halo, cyano, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, C 1-6 alkanoyl, C 1-6 haloalkanoyl, —S(O) n C 1-6 alkyl, —S(O) n C 1-6 haloalkyl and pentafluorothio;

R 2 is cyano;

R 3 is C 1-6 alkyl, C 1-6 haloalkyl, or —(C 0-3 alkylene)-phenyl;

R 4 is hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, —(C 0-3 alkylene)-R 7 or (C 1-3 alkylene)-R 8 ;

R 5 is hydrogen;

R 6 is C 1-6 alkyl or C 1-6 haloalkyl;

R 7 is C 3-8 cycloalkyl, —S(O) n R 9 , phenyl, het, —CO 2 R 6 or C(O)N(R a )R b ;

R 8 is hydroxy, C 1-6 alkoxy, C 1-6 haloalkoxy, cyano, —N(R a )R b or —O—C(O)R 6 ;

R 9 is C 1-6 alkyl, C 1-6 haloalkyl, C 3-8 cycloalkyl, —N(R a )R b , phenyl or het;

R a and R b independently represent hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, C 2-6 alkenyl or C 2-6 haloalkenyl, or R a additionally is —(C 0-3 alkylene)-C 3-8 cycloalkyl, —(C 0-3 alkylene)-phenyl or —(C 0-3 alkylene)-het, or together R a and R b form a 4- to 7-membered ring, optionally substituted by one or more groups independently selected from the group consisting of halo, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy and C 1-6 haloalkoxy;

n is the integer 0, 1 or 2;

where het represents a four- to seven-membered heterocyclic group, which is aromatic or non-aromatic and which contains one or more heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur and mixtures thereof,

where both phenyl and het may be optionally substituted, where the valence allows, by one or more substituents independently selected from the group consisting of halo, hydroxy, cyano, nitro, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkenyl, C 1-6 haloalkenyl, C 1-6 alkoxy, C 1-6 haloalkoxy, C 3-8 cycloalkyl, C 1-6 alkanoyl, C 1-6 haloalkanoyl, C 1-6 alkylcarbonyloxy, C 1-6 alkoxycarbonyl and NR a R b ;

where C 3-8 cycloalkyl may be optionally substituted by one or more groups independently selected from the group consisting of halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkenyl C 1-6 haloalkenyl, hydroxy, C 1-6 alkoxy and C 1-6 haloalkoxy; and

where any alkylene group may be optionally substituted by one or more halo.

2. The compound according to claim 1 , wherein R 1 is a phenyl group which bears chloro substituents at the 2- and 6-positions, and a substitutent at the 4-position selected from the group consisting of trifluoromethyl, difluoromethoxy, trifluoromethoxy, trifluoromethlythio and pentafluorothio.

3. The compound according to claim 1 , wherein R 3 is methyl, ethyl, trifluoromethyl, or 2,2,2-trifluoroethyl.

4. The compound according to claim 3 , wherein R 3 is methyl.

5. The compound according to claim 1 , wherein R 4 is hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, —(C 0-3 alkylene)-C 3-8 cycloalkyl, cyanomethyl, 2-hydroxyethyl, —(C 1-2 alkylene)-het, —(C 0-3 alkylene)-phenyl, —(C 0-1 alkylene)-S(O) n R 9 , —(C 1-3 alkylene)-O—C(O)R 6 , —(C 1-3 alkylene)-C(O)N(R a )R b or —CO 2 R 6 .

6. The compound according to claim 5 , wherein R 4 is hydrogen, methyl, ethyl, trifluoromethyl, 2,2-difluoroethytl, 2,2,2-trifluoroethyl, methylsulfonyl, trifluoromethylsulfonyl, 2,2,2-trifluoroethylsulfonyl, aminosulfonyl, N,N-dimethylaminosulfonyl, methylsulfonymethyl, cyclopropyl, cyclobutyl, cyclopropylmethyl, 1-(trifluoromethyl)cyclopropylmethyl, cyanomethyl, methoxycarbonyl, triazolylethyl, pyrimidin-4-ylmethyl, 1,2,4-oxadiazol-3-ylmethyl, pyrazol-3-ylmethyl, 1-methyl-1H-imidazol-2-yl, 5-methyl-isoaxazol-3-ylmethyl, 2-pyridin-4-ylethyl, aminocarbonylmethyl, benzyl or 4-fluorobenzyl.

7. The compound of claim 1 selected from the group consisting of:

N-{3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-1H-pyrazol-4-yl}-1,1,1-trifluoro-N-methylmethanesulfonamide;

N-{3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-1H-pyrazol-4-yl}-N-(methylsulfonyl)methanesulfonamide;

N-{3-cyano-1-[2,6-dichloro-4-pentafluorothiophenyl]-1H-pyrazol-4-yl}-N-(methylsulfonyl)methanesulfonamide;

N-{3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-1H-pyrazol-4-yl}methanesulfonamide;

N-{3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]1H-pyrazol-4-yl}-2,2,2-trifluoroethanesulfonamide;

N-{3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-1H-pyrazol-4-yl}-2,2,2-trifluoro-N-(methylsulfonyl)ethanesulfonamide; and

N-{3-cyano-1-[2,6dichloro-4-(trifluoromethyl)phenyl]-1H-pyrazol-4-yl}-N-(2,2,2-trifluoroethyl)methanesulfonamide;

or a pharmaceutically, veterinarily or agriculturally acceptable salt thereof.

8. A pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically, veterinarily or agriculturally acceptable salt thereof,

wherein:

R 1 is phenyl, optionally substituted by one or more groups independently selected from the group consisting of halo, cyano, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy, C 1-6 haloalkoxy, C 1-6 alkanoyl, C 1-6 haloalkanoyl, —S(O) n C 1-6 alkyl, —S(O) n C 1-6 haloalkyl and pentafluorothio;

R 2 is cyano;

R 3 is C 1-6 alkyl, C 1-6 haloalkyl, or —(C 0-3 alkylene)-phenyl;

R 4 is hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, —(C 0-3 alkylene)-R 7 or —(C 1-3 alkylene)-R 8 ,

R 5 is hydrogen;

R 6 is C 1-6 alkyl or C 1-6 haloalkyl;

R 7 is C 3-8 cycloalkyl, —S(O) n R 9 , phenyl, het, —CO 2 R 6 or C(O)N(R a )R b ;

R 8 is hydroxy, C 1-6 alkoxy, C 1-6 haloalkoxy, cyano, —N(R a )R b or —O—C(O)R 6 ;

R 9 is C 1-6 alkyl, C 1-6 haloalkyl, C 3-8 cycloalkyl, —N(R a )R b , phenyl or het;

R a and R b independently represent hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, C 2-6 alkenyl or C 2-6 haloalkenyl or R a additionally is —(C 0-3 alkylene)-C 3-8 cycloalkyl, —(C 0-3 alkylene)-phenyl or —(C 0-3 alkylene)-het, or together R a and R b form a 4- to 7-membered ring, optionally substituted by one or more groups independently selected from the group consisting of halo, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkoxy and C 1-6 haloalkoxy;

n is the integer 0, 1 or 2;

where het represents a four- to seven-membered heterocyclic group, which is aromatic or non-aromatic and which contains one or more heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur and mixtures thereof;

where both phenyl and het may be optionally substituted, where the valence allows, by one or more substituents independently selected from the group consisting of halo, hydroxy, cyano, nitro, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkenyl, C 1-6 haloalkenyl, C 1-6 alkoxy, C 1-6 haloalkoxy, C 3-8 cycloalkyl, C 1-6 alkanoyl, C 1-6 haloalkanoyl, C 1-6 alkylcarbonyloxy, C 1-6 alkoxycarbonyl and NR a R b ;

where C 3-8 cycloalkyl may be optionally substituted by one or more groups independently selected from the group consisting of halo, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 alkenyl, C 1-6 haloalkenyl, hydroxy, C 1-6 alkoxy and C 1-6 haloalkoxy; and

where any alkylene group may be optionally substituted by one or more halo.