Parasiticidal pyrazoles

Abstract

Compounds of formula (I): or pharmaceutically, veterinarily or agriculturally acceptable salts thereof, or pharmaceutically, veterinarily or agriculturally acceptable solvates of either entity, wherein R 1 is 2,4,6-trisubstituted phenyl or 3,5-disubstituted pyridin-2-yl; R 3 is hydrogen; C 2 to C 5 alkyl substituted with one or more halo and with hydroxy; C 2 to C 5 alkanoyl substituted with one or more halo; C 2 to C 6 alkenyl optionally substituted with one or more halo; halo; amino or CONH 2 ; R 5 is hydrogen, amino or halo; R 2 and R 4 are each independently selected from hydrogen, fluoro, chloro and bromo; R 6 and R 8 are hydrogen; and R 7 is hydrogen or C 1 to C 4 alkyl optionally substituted with one or more halo; are parasiticidal agents.

1 . A compound of formula (I):  
       
         
           
           
               
               
           
         
       
       or a pharmaceutically, veterinarily or agriculturally acceptable salt thereof, or a pharmaceutically, veterinarily or agriculturally acceptable solvate of either entity,  
       wherein 
 R 1  is 2,4,6-trisubstituted phenyl wherein the 2- and 6-substituents are each independently selected from halo and the 4-substituent is selected from C 1  to C 4  alkyl optionally substituted with one or more halo, halo and pentafluorothio; or 3,5-disubstituted pyridin-2-yl wherein the 3-substituent is halo and the 5-substituent is selected from C 1  to C 4  alkyl optionally substituted with one or more halo, halo and pentafluorothio;  
 R 3  is hydrogen; C 2  to C 5  alkyl substituted with one or more halo and with hydroxy; C 2  to C 5  alkanoyl substituted with one or more halo; C 2  to C 6  alkenyl optionally substituted with one or more halo; halo; amino or CONH 2 ;  
 R 5  is hydrogen, amino or halo;  
 R 2  and R 4  are each independently selected from hydrogen, fluoro, chloro and bromo;  
 R 6  and R 8  are hydrogen; and  
 R 7  is hydrogen or C 1  to C 4  alkyl optionally substituted with one or more halo.  
 
     
     
         2 . A compound according to  claim 1  wherein R 1  is 2,6-dichloro-4-trifluoromethylphenyl, 2,6-dichloro-4-pentafluorothiophenyl, 2,4,6-trichlorophenyl or 3-chloro-5-trifluoromethylpyridin-2-yl; R 3  is hydrogen; hydroxytrihaloethyl; trihaloacetyl; C 2  to C 3  alkenyl optionally substituted with one or more halo; halo; amino or CONH 2 ; R 5  is hydrogen or amino; R 2  and R 4  are each independently selected from hydrogen, chloro and bromo; and R 7  is hydrogen or trifluoromethyl.  
     
     
         3 . A compound according to  claim 2  wherein R 1  is 2,6-dichloro-4-trifluoromethylphenyl or 3-chloro-5-trifluoromethylpyridin-2-yl; R 3  is hydrogen; 1-hydroxy-2,2,2-trifluoroethyl; trifluoroacetyl; ethenyl; 2,2-difluoroethenyl; 2,2-dibromoethenyl; propen-2-yl; chloro; bromo; iodo; amino or CONH 2 ; and R 2  and R 4  are bromo.  
     
     
         4 . A compound according to  claim 3  wherein R 3  is hydrogen; ethenyl; 2,2-difluoroethenyl; chloro; bromo or CONH 2 .  
     
     
         5 . A veterinary or agricultural formulation comprising a compound of formula (I), or a veterinarily or agriculturally acceptable salt thereof, or a veterinarily or agriculturally acceptable solvate of either entity, according to any one of  claims 1  to  4 , together with a veterinarily or agriculturally acceptable diluent or carrier.  
     
     
         6 . A pharmaceutically composition comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of either entity, according to any one of  claims 1  to  4 , together with a pharmaceutically acceptable diluent or carrier.  
     
     
         7 . A veterinary or agricultural formulation according to  claim 5 , or a pharmaceutical composition according to  claim 6 , which is adapted for topical administration.  
     
     
         8 . A compound of formula (I), or a veterinarily or agriculturally acceptable salt thereof, or a veterinarily or agriculturally acceptable solvate of either entity, according to any one of  claims 1  to  4 , or a veterinarily or agriculturally acceptable formulation containing any of the foregoing according to  claim 5  or  claim 7 , for use as a parasiticide.  
     
     
         9 . A compound of formula (I), or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of either entity, according to any one of  claims 1  to  4 , or a pharmaceutical composition containing any of the foregoing according to  claim 6  or  claim 7 , for use as a medicament.  
     
     
         10 . The use of a compound of formula (I), or a pharmaceutically or veterinarily acceptable salt thereof, or a pharmaceutically or veterinarily acceptable solvate of either entity, according to any one of  claims 1  to  4 , or a pharmaceutical composition or veterinary formulation containing any of the foregoing according to any one of  claims 5  to  7 , for the manufacture of a human or animal parasiticidal medicament.  
     
     
         11 . A method of treating a parasitic infestation in an animal (including a human being) which comprises treating said animal with an effective amount of a compound of formula (I), or a pharmaceutically or veterinarily acceptable salt thereof, or a pharmaceutically or veterinarily acceptable solvate of either entity, according to any one of  claims 1  to  4 , or a pharmaceutical composition or veterinary formulation containing any of the foregoing according to any one of  claims 5  to  7 .  
     
     
         12 . A method of treating a parasitic infestation at a locus which comprises treating said locus with an effective amount of a compound formula (I), or a veterinarily or agriculturally acceptable salt thereof, or a veterinarily or agriculturally acceptable solvate of either entity, according to any one of  claims 1  to  4 , or a veterinary or agricultural formulation containing any of the foregoing according to  claim 5  or  claim 7 .  
     
     
         13 . A method as defined in  claim 12  wherein the locus is the skin or fur of an animal, or a plant surface, or the soil around the plant to be treated.