It is generally a goal of agronomists and veterinarians to possess sufficient means to control pests, particularly arthropods, when they attempt to invade or attack mammals, particularly domestic animals and/ or livestock. A classical method of controlling such pests has been the use of topical and/or systemic pesticides on or in the domestic animal which is being attacked. Generally effective treatments include the oral administration of insect growth regulators, such as lufenuron, or antihelminth compounds such as an ivermectin or an avermectin, or the topical application of the insecticide fipronil. It is advantageous to apply pesticides to animals in oral form so as to prevent the possible contamination of humans or the surrounding environment.

It is an object of the present invention to provide new pesticides which may be used in domestic animals.

Another object of the invention is to provide safer pesticides for domestic animals.

Another object of the invention is to provide new pesticides for domestic animals that may be used in lower doses than existing pesticides.

These objects are met in whole or in part by the present invention.

The present invention provides a method of controlling parasites in or on an animal comprising administering orally to the animal a parasiticidally effective, substantially non-emetic amount oral- arylpyrazole of formula (I): wherein: R1 is cyano, acetyl, C (S) NH2, alkyl, haloalkyl, C (=NOH) NH2 or C (=NNH2) NH2; R2 is S (O) nR3; C2-C3 alkenyl, C2-C3 haloalkenyl, cycloalkyl, halocycloalkyl or C2-C3 alkynyl; R3 is alkyl or haloalkyl; R4 is-N=C (R5)-Z-R6,-N=C (R5)-N (R7)-R8, or <BR> <BR> <BR> <BR> -N (R9)-C (R5) =NR6 ;<BR> <BR> <BR> <BR> <BR> Rs is hydrogen; alkyl; or alkyl substituted by halogen, alkoxy,<BR> <BR> <BR> <BR> <BR> <BR> haloalkoxy or-S (O) mRI 5; R6 and R7 each independently represent hydrogen, alkyl, C3-C5 alkenyl or C3-Cs alkynyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) mR15 ; or alkyl substituted by phenyl or pyridyl each of which is optionally substituted with one or more groups selected from halogen, nitro and alkyl; or R6 and R7 may form together with the nitrogen to which they are attached a 3 to 7 membered ring which may additionally contain one or more heteroatoms selected from oxygen, nitrogen or sulfur;

R8 is alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, R14CO-or-S (O) tRio; andR14arealkylorhaloalkyl;R9,R10 R11 and R12 are independently selected from halogen, hydrogen, CN and N02; R13 is selected from halogen, haloalkyl, haloalkoxy,-S (O) qCF3, and-SFs; R15 is alkyl or haloalkyl; X is selected from nitrogen and C-R12; Z is O, S (O) a; or NR7; a, m, n and q are independently selected from 0,1, and 2; and t is 0 or 2; and veterinarily acceptable salts thereof.

In another aspect, the present invention provides a method of controlling parasites in or on an animal comprising administering orally to the animal a parasiticidally effective, substantially non-emetic amount of a 1-arylpyrazole of formula (XX): (XX) wherein: R201 is cyano, C (O) alkyl, C (S) NH2, alkyl, C (=NOH) NH2 or C (=NNH2) NH2 ;

R202 is S (O) hR203 C2-C3 alkenyl, C2-C3 haloalkenyl, cycloalkyl, halocycloalkyl or C2-C3 alkynyl; R203 is alkyl or haloalkyl; R204 is-N (R205) C (O) CR206R207R208N (R205) C O) aryl, or -N (R205) C O) OR207 ; R205 is alkyl, haloalkyl, cycloalkyl, halocycloalkyl, <BR> <BR> <BR> <BR> <BR> cycloalkylalkyl, halocycloalkylalkyl, alkoxyalkyl, haloalkoxyalkyl, C3-<BR> <BR> <BR> <BR> <BR> <BR> C5 alkenyl, C3-C5 haloalkenyl, C3-C5 alkynyl, C3-C5 haloalkynyl; R206 is hydrogen, halogen, alkoxy, haloalkoxy, alkoxyalkyl, haloalkoxyalkyl, formyloxy, alkylcarbonyloxy, haloalkylcarbonyloxy, alkylthio, haloalkylthio, alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl, haloalkylsulfonyl, alkylamino, dialkylamino, haloalkylamino, di (haloalkyl) amino, cycloalkyloxy, halocycloalkyloxy, alkoxyalkoxy, haloalkoxyalkoxy, alkoxyalkoxyalkoxy, aryloxy, or arylalkoxy; R207 and R208 are independently hydrogen, alkyl, haloalkyl, cycloalkyl, or halocycloalkyl; or R207 and R208 may form together with the carbon to which they are attached a 3 to 7 membered ring which additionally may contain one or more heteroatoms selected from nitrogen, oxygen and sulfur; Xl is selected from nitrogen and C-R212; R211 and R212 are independently selected from halogen, hydrogen, CN and NO2; R213 is selected from halogen, haloalkyl, haloalkoxy,-S (O) kCF3, and-SF; and h and k are independently selected from 0,1, and 2; and veterinarily acceptable salts thereof.

By the term"veterinarily acceptable salts"is meant salts the anions of which are known and accepted in the art for the formation of salts for veterinary use. Suitable acid addition salts, e. g. formed by

compounds of formulae (I) and (XX) containing a basic nitrogen atom, e. g. an amino group, include salts with inorganic acids, for example hydrochlorides, sulphates, phosphates and nitrates and salts with organic acids for example acetic acid.

Unless otherwise specified, alkyl and alkoxy groups are generally lower alkyl and alkoxy groups, that is having from one to six carbon atoms, preferably from one to four carbon atoms. Generally, the haloalkyl, haloalkoxy and alkylamino groups have from one to four carbon atoms. The haloalkyl and haloalkoxy groups can bear one or more halogen atoms; preferred groups of this type include-CF3 and- OCF3. Cycloalkyl groups generally have from 3 to 6 carbon atoms, preferably from 3 to 5 carbon atoms and may be substituted by one or more halogen atoms.. Alkenyl, haloalkenyl, alkynyl, and haloalkynyl groups generally contain from 3 to 5 carbon atoms. By the term aryl is generally meant phenyl, pyridyl, furyl, and thiopheneyl, each of which is optionally substituted by one or more halogen, alkyl, haloalkyl, nitro, alkoxy, haloalkoxy, hydroxy, amino, alkylamino or dialkylamino. In compounds of formula (I), by the term substituted alkyl is meant alkyl which is substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) mRls; or alkyl substituted by phenyl or pyridyl each of which is optionally substituted with one or more groups selected from halogen, nitro and alkyl; wherein RI 5 is alkyl or haloalkyl and m is zero, one or two. Preferably in compounds of formula (I), alkyl groups are generally substituted by from one to five halogen atoms, preferably from one to three halogen atoms. Chlorine and fluorine atoms are preferred.

Compounds of formula (I) wherein R4 is-N=C (R5)-Z-R6, Z is NR7 and R6 represents a hydrogen atom may exist as the tautomeric

double bond isomer form-NH-C (Rs) =N-R7. It is to be understood that both such forms are embraced by the present invention.

In compounds of formula (XX) the following examples of radicals are provided: An example of cycloalkylalkyl is cyclopropylmethyl; an example of cycloalkoxy is cyclopropyloxy; an example of alkoxyalkyl is CH30CH2- ; an example of alkoxyalkoxy is CH30CH20- ; An example of alkoxyalkoxyalkoxy is CH3OCH2OCH2O-; An example of aryloxy is the phenoxy radical; and An example of the arylalkoxy radical is benzyloxy or 2- phenylethoxy.

Generally, in dialkylamino or di (haloalkyl) amino radicals, the alkyl and haloalkyl groups on nitrogen may be chosen independently of one another.

It is also to be understood that enantiomeric and diastereomeric forms of the compounds of formulae (I) and (XX) and salts thereof are embraced by the present invention. Compounds of formula (I) may be generally prepared according to known processes, for example as described in European Patent Application 511845 or other processes according to the knowledge of a man skilled in the art of chemical synthesis.

By the term non-emetic is meant a compound that does not generally elicit emesis from the animal when a protective, preventative or cleaning dose is administered to the animal. By the term emesis is meant vomiting. Generally an emetic substance elicits the said emesis in less than 24 hours after administration, preferably less than 8 hours, more preferably less than 2 hours. Generally when the compounds of the invention are administered to a population of animals, more than

70% of the animals are free of emesis, preferably more than 80%, most preferably more than 90%.

A preferred class of compounds of formula (I) for use in the control of parasites in animals are those wherein: RI is cyano or alkyl; R2 is S (O) nR3 ; R3 is alkyl or haloalkyl; R4 is-N=C (R5)-Z-R6; Rs is hydrogen, alkyl or haloalkyl; Z is O, S (O) a; or NR7; R6 and R7 are independently selected from hydrogen and unsubstituted or substituted alkyl; or R6 and R7 may form together with the nitrogen to which they are attached a 3 to 7 membered ring which may additionally contain one or more heteroatoms selected from oxygen, nitrogen or sulfur; X is selected from nitrogen and C-R12 ; Rl 1 and R12 are independently selected from halogen, hydrogen, CN and NO; R13 is selected from halogen, haloalkyl, haloalkoxy,-S (O) qCF3, and-SFs; a, n and q are independently selected from 0,1, and 2.

3) Preferably R6 is alkyl which is substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, sulfide, sulfoxide, sulfone, or phenyl or pyridyl moieties of which each phenyl or pyridyl moiety is optionally substituted with one or more groups selected from halo, nitro, and alkyl.

Preferably the method of the invention has one or more of the following features:

RI is cyano; R4 is-N=C (Rs)-Z-R6 and Z is-NR7; X is C-R12 ; R11 and R12 represent a chlorine atom; and R13 is CF3, OCF3 or-SFs; R12 is-S (O) nCF3 and n is 0,1, or 2.

A further preferred class of compounds of formula (I) for use in the control of parasites in animals are those wherein: Rl is cyano or alkyl; R4 is-N=C (R5)-Z-R6; and Rs is hydrogen alkyl.orC1-C3 The compounds of formula (I) for use in the control of parasites in animals, preferably have one or more of the following features: RI is cyano or methyl; R3 is halomethyl (preferably CF3); Rl 1 and R12 each independently represent a halogen atom; X is C-R12; R13 is haloalkyl (preferably CF3), haloalkoxy (preferably OCF3), or-SFs; or n is 0,1 or 2 (preferably 0 or 1).

A further preferred class of compounds of formula (I) for use in the control of parasites in animals are those wherein: R1 is cyano; R2 is S (O) nR3 ; R3 is halomethyl; R4 is-N=C (R5)-Z-R6; Z is NR7; Rs is hydrogen or alkyl;

R6 and R7 each independently represent hydrogen, alkyl, alkenyl or alkynyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) mRI 5; or alkyl substituted by phenyl or pyridyl which rings are optionally substituted with one or more groups selected from halogen, nitro and alkyl; X is selected from nitrogen and C-R12; R11 and Rl2 each independently represent a halogen atom; R13 is selected from haloalkyl, haloalkoxy and-SFs; R15 is alkyl or haloalkyl; and m and n are independently selected from 0,1, and 2.

A further preferred class of compounds of formula (I) for use in the control of parasites in animals is that wherein: Ri is cyano; R2 is S (O) nCF3 ; R4 is-N=C (R5)-Z-R6 or-N=C (R5)-N (R7)-Rg; Z is NR7; Rs is hydrogen or alkyl; R6 and R7 each independently represent hydrogen, alkyl, alkenyl or alkynyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) mR15; or methyl substituted by phenyl or pyridyl which rings are optionally substituted with one or more groups selected from halogen, nitro and alkyl; R8 is alkoxy, haloalkoxy, amino, alkylamino, dialkylamino or -S (0) tRio ; X is selected from nitrogen and C-R12; RI g and R1 5 independently represent alkyl or haloalkyl;

R1 1 and R12 each represent a chlorine atom; R13 is CF3 or-SFs; and m and n are 0,1 or 2; and t is 0 or 2.

A further preferred class of compounds of formula (I) for use in the control of parasites in animals are those wherein: R1 is cyano; R2 is S (O) nCF3 ; R4 is-N=C (R5)-Z-R6; Z is NR7; Rs is hydrogen or methyl; R6 and R7 each independently represent hydrogen, alkyl, alkenyl or alkynyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) mR15; or alkyl substituted by phenyl or pyridyl which rings are optionally substituted with one or more groups selected from halogen, nitro and alkyl; X is C-R12; R11 and R12 each represent a chlorine atom; CF3or-SF5;R13is R15 is alkyl or haloalkyl; m is zero, one or two; and n is 0 or 1.

A further preferred class of compounds of formula (I) for use in the control of parasites in animals are those wherein: RI is cyano; R2 is S (O) nCF3 ; R4 is-N=C (R5)-Z-R6; Z is NR7;

Rs and R7 each represent a hydrogen atom; R6 is alkyl or haloalkyl; C-R12;Xis R11 and R12 each represent a chlorine atom; CF3or-SF5;andR13is nits0.

Compounds of formula (XX) which are preferred according to the present invention are those wherein: wherein: <BR> <BR> <BR> <BR> <BR> <BR> R201 is cyano;<BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> R202 is S (O) hR203 ; R203 is alkyl or haloalkyl; R204 is-N (R205) C (O) CR206R207R208 ; R205 is alkyl, haloalkyl, cycloalkyl, cycloalkylalkyl and halocycloalkylalkyl; R206 is alkoxy, haloalkoxy, or hydrogen; R207 and R208 are independently hydrogen, alkyl, or haloalkyl; or R207 and R208 may form together with the carbon to which they are attached a 3 to 7 membered ring which additionally may contain one or more heteroatoms selected from nitrogen, oxygen and sulfur; X1 is selected from nitrogen and C-R212 ; R211 and R212 are independently selected from halogen, hydrogen, CN and NO2; R213 is selected from halogen, haloalkyl, haloalkoxy,-S (O) kCF3, and-SF; and h and k are independently selected from 0,1, and 2.

A preferred group of compounds of formula (XX) is that wherein the ring which is formed by R207 and R208 is interrupted by one or more heteroatoms, more preferably one oxygen atom.

The compounds of formula (I) of the present invention preferably have one or more of the following features: R201 is cyano; R203 is halomethyl, preferably CF3; R21 nd R212 are independently halogen; Xi is C-R212 ; R213 is haloalkyl, haloalkoxy or-SFs; or h is 0 or 1, or 2, preferably 0 or 1.

A preferred class of compounds that wherein R204 is N (R205) C (O) CR206R207R208.

Another preferred class of compounds that wherein R204 is N (R205) C (0) aryl.

Another preferred class of compounds that wherein R204 is N (R205) C O) OR207.

Preferably R205 is C,-C4 alkyl, more preferably C,-C2 alkyl, most preferably methyl.

Preferably R206 is alkoxy, most preferably methoxy, ethoxy or propoxy.

Preferably R207 and R208 are both hydrogen.

Among the compounds which may be used in the invention some are new and hence in another aspect of the present invention there is provided a compoundof formula (II): wherein: R21 is cyano, alkyl, haloalkyl,, acetyl or-C (=S) NH2, C (=NOH) NH2 or C (=NNH2) NH2 ; R22 is S (O) mR23 ; R23 is alkyl or haloalkyl; R24 or-N=C(R25)-N(R27)-R28;-N=C(R25)N(R26)(R27) R25 represents hydrogen or alkyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy or-S (O) mR35; R26 and R27 each independently represent hydrogen, alkyl, alkenyl or alkynyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) mR35; or alkyl substituted by phenyl or pyridyl which rings are optionally substituted with one or more groups selected from halogen, nitro and alkyl; wherein R35 is alkyl or haloalkyl and m is zero, one or two; X is selected from nitrogen and C-R32 ; R28 is alkoxy, haloalkoxy, amino, alkylamino, dialkylamino or -S(O)tR30; R30 is alkyl or haloalkyl; R31 and R32 are independently selected from halogen, hydrogen, CN and N02;

R33 is selected from halogen, haloalkyl, haloalkoxy,-S (O) rCF3, and-SFS; m and r are independently selected from 0,1, and 2; and t is 0 or 2; with the exclusion of the compound wherein R21 is cyano; R22 is- SCF2CH3; R25 is hydrogen; X is C-R32; R26 and R27 are methyl; R31 and R32 are chlorine; and R33 is trifluoromethyl; and veterinarily acceptable salts thereof.

A further class of novel compounds of formula (II) are those wherein: R21 is cyano or methyl; R22 is S (O) mR23 ; R23 is haloalkyl; R24 is-N=C (R25) N (R26) (R27) ; R25 and R27 are hydrogen or unsubstituted or substituted alkyl; R26 is haloalkyl; X is selected from nitrogen and C-R32 ; R31 and R32 are independently selected from halogen, hydrogen, CN and N02; R33 is selected from halogen, haloalkyl, haloalkoxy,-S (O) rCF3, and-SFS; m and r are independently selected from 0,1, and 2; with the exclusion of the compound wherein R21 is cyano; R22 is-SCF2CH3; R25 is hydrogen; X is C-R32; R26 and R27 are methyl; R31 and R32 are chlorine; and R33 is trifluoromethyl.

A preferred class of novel compounds of formula (II) are those wherein: R21 is cyano; R22 is S (O) mR23;

R23 is halomethyl; R24 is-N=C (R25) N (R26) (R27) ; R25 is hydrogen or alkyl; R26 and R27 each independently represent hydrogen, alkyl, alkenyl or alkynyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) mR15; or alkyl substituted by phenyl or pyridyl each of which is optionally substituted with one or more groups selected from halogen, nitro and alkyl; wherein R1 5 is alkyl or haloalkyl and m is zero, one or two; X is selected from nitrogen and C-R32; R31 and R32 each represent a chlorine atom; R33 is selected from haloalkyl, haloalkoxy and-SFs; m is selected from 0,1, and 2.

A further preferred class of novel compounds of formula (II) are those wherein: R21 is cyano; R22 is S (O) mCF3; R24 is-N=C (R25) N (R26) (R27) ; or-N=C (R25)-N (R27)-R28 ; R25 is hydrogen or methyl; R26 and R27 each independently represent hydrogen, alkyl, alkenyl or alkynyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) mR15; or methyl substituted by phenyl or pyridyl which rings are optionally substituted with one or more groups selected from halogen, nitro and alkyl; wherein R15 is alkyl or haloalkyl and m is zero, one or two; R28 is alkoxy, haloalkoxy, amino, alkylamino, dialkylamino or -S (O) tR30 ; X is selected from nitrogen and C-R32;

R30 is alkyl or haloalkyl; R31 and R32 each represent a chlorine atom; R33 is CF3 or-SFs; and m is 0, 1 or 2; and t is 0 or 2.

A more preferred class of novel compounds of formula (II) are those wherein: <BR> <BR> <BR> <BR> <BR> R21 is cyano;<BR> <BR> <BR> <BR> <BR> <BR> R22 is S (O) mCF3;<BR> <BR> <BR> <BR> <BR> <BR> R24 is-N=C (R25) N (R26) (R27) ; R25 and R27 each independently represent hydrogen or methyl; R26 represents hydrogen, alkyl, alkenyl or alkynyl; or alkyl substituted by one or more halogen, alkoxy, haloalkoxy, amino, alkylamino, dialkylamino, cyano or-S (O) merls; or methyl substituted by phenyl or pyridyl which rings are optionally substituted with one or more groups selected from halogen, nitro and alkyl; wherein RI 5 is alkyl or haloalkyl and m is zero, one or two; X is selected from nitrogen and C-R32; R31 and R32 each represent a chlorine atom; R33 is CF3 or-SFs; and m is 0,1 or 2.

An especially preferred class of novel compounds of formula (II) are those wherein: R21 is cyano; R22 is S (O)mCF3; R24 is-N=C (R25) N (R26) (R27) ; R25 and R27 each represent a hydrogen atom; R26 is alkyl or (preferably) haloalkyl; X is C-R32;

R31 and R32 each represent a chlorine atom; R33 is CF3 or-SFs; and m is 0.

In another aspect of the present invention there is provided an compound of formula (XX) or a salt thereof as hereinbefore defined, provided that the compound is not 3-cyano-1- (2,6-dichloro-4- trifluoromethylphenyl)-5- (N-ethoxycarbonyl-N-methyl) amino-4- trifluoromethylthiopyrazole.

Most preferably, the following compounds of formula (I) and (XX) are preferred according to the present invention as listed in Tables 1 to 13. The Compound Numbers are for identification purposes only.

The following symbols are hereby defined: Me means methyl; Et means ethyl; n-Pr means n-propyl; i-Pr means isopropyl; n-Bu means n-Butyl, and n-Pent means n-Pentyl; Cy means cyclopropyl.

Table 1 Compounds of formula (I) wherein RI is cyano; R2 is SCF3; RI 1 is Cl, X is C-Cl, R4 is-N=C (R5) ZR6, Z is NR7, R7 is H, and R13 is CF3 or SFs. Compound Compound Number Number R5 R6 R13=CF3 R13=SF5 201-1 201-2 Me Me 202-1 202-2 Me Et 203-1 203-2 Me n-Pr 204-1 204-2 Me i-Pr 205-1 205-2 Me n-Bu 206-1 206-2 H H 207-1 207-2 H Et 208-1 208-2 H n-Pr 209-1 209-2 H i-Pr 210-1 210-2 H n-Bu 211-1 211-2 H CH2CF3 212-1 212-2 H (CH2) 2CF3 213-1 213-2 H CH20Me H(CH2)2OCF3214-1214-2 215-1 215-2 Me CH2CF3 216-1 216-2 Me (CH2) 2CF3 Me(CH2)2OMe217-1217-2 Me(CH2)2NMe2218-1218-2 Table 2 Compounds of formula (I) wherein Rl is cyano; Rl l is Cl; R4 is- N=C (R5) ZR6 and Z is NR7. Cmp R2 R5 R6 R7 X R13 d No. 219 SCF3 H CH3 CH3 C-Cl CF3 220 S02CF3 H CH3 CH3 C-Cl CF3 221 SCF3 H CH2CN H C-Cl CF3 222 SCF3 H CH3 H C-Cl CF3 223 SOCF3 H CH2Ph H C-Cl CF3 224 SCF3 H CH2Ph H C-Cl CF3 225 SOCF3 H CH3 H C-Cl CF3 226 SOCF3 H CH3 H C-Cl CF3 227 SOCF3 H CH2CF3 H C-Cl CF3 228 S02CF3 H 2-propynyl H C-Cl CF3 229 S02CF3 H CH2Ph H C-Cl CF3 230 S02CF3 H CH2CF3 H C-Cl CF3 231 SOCF3 H CH3 CH3 C-Cl CF3 232 SCF3 H CH2CF3 H C-C1 CF3 233 SCF3 H CH2CF3 H C-Cl CF3 234 SCF3 H 2-propenyl H C-Cl CF3 235 SCF3 H 2-propynyl H C-Cl CF3 236 SOCF3 H 2-propynyl H C-Cl CF3 237 SCF3 H CH20Et H N CF3 HCH2OCH2CF3CH3C-ClCF3238SCF3 239 S02CF3 H CH2CF3 CH3 C-Cl SF5 240 SCF3 H CH2CF3 H N SF5 241 SOCF3 H CH2CH2CF3 H C-Cl CF3 242 S02CF3 H (CH2) 3CF3 H C-Cl CF3 243 SCF3 H (CH2) 2N (CH3) 2 H C-Cl CF3 244 SO2CF3 CH3 CH2 (4-Cl Ph) H C-Cl CF3 HCH2SO2CF3HC-ClCF3245SCF3 246 SCF3 H CH2 (4-pyridyl) H C-Cl CF3 HCH2(3-NO2Ph)HC-ClCF3247SCF3 248 SCF3 H CH2CH2SCH3 H C-Cl CF3 249 SOCF3 H CH2CF3 CH3 C-C1 CF3

Note: Compound number 232 is the acetate salt, and compound number 233 is the citrate salt.

Table 3 Compounds of formula (I) wherein RI is cyano; R1 1 is Cl; and R4 is-N=C (R5)-N (R7)-R8. Cmpd R2 R5 R8 R7 X R13 No. HOEtHC-ClCF3250SCF3 251 SCF3 H NHCH3 H C-Cl CF3 252 SCF3 H NHCH3 CH3 C-Cl CF3 253 SCF3 H OCH2CF3 H C-Cl CF3 254 SCF3 H N (CH3) 2 H N SF5 255 SCF3 H NH2 H C-Cl CF3 256 SCF3 H S-nPr H C-Cl CF3 257 S02CF3 Et S-nPr H C-Cl SF5 258 SCF3 H S02CH3 H C-Cl CF3

The following compounds of formula (XX) are preferred according to the present invention as listed in Tables 4-12.

Table 4 Compounds of formula (XX) wherein R201 is cyano; R202 is SCF3; R204 is N (R205) C (O) CR206R207R208 R207 and R208 =H; R211 is Cl, XI is C-Cl, and R213is CF3 or SF5. Compound Compound R205 R206 Number Number (R213=CF3)(R213=SF5) MeH1-11-2 2-1 2-2 Me OMe 3-1 3-2 Me OEt MeO-i-Pr4-14-2 MeO-n-Bu5-15-2 6-1 6-2 Et H 7-1 7-2 Et OMe 8-1 8-2 Et OEt EtO-i-Pr9-19-2 10-1 10-2 Et O-n-Bu n-PrH11-111-2 12-1 12-2 n-Pr OMe 13-1 13-2 n-Pr OEt 14-1 14-2 n-Pr O-i-Pr 15-1 15-2 n-Pr O-n-Bu 16-1 16-2 i-Pr H 17-1 17-2 i-Pr OMe 18-1 18-2 i-Pr OEt 19-1 19-2 i-Pr O-i-Pr 20-1 20-2 i-Pr O-n-Bu n-BuH21-121-2 22-1 22-2 n-Bu OMe 23-1 23-2 n-Bu OEt 24-1 O-i-Prn-Bu 25-1 25-2 n-Bu 0-n-Bu CH2CyH26-126-2 CH2CyOMe27-127-2 28-1 OEtCH2Cy CH2CyO-i-Pr29-129-2 CH2CyO-n-Bu30-130-2 CH2CCHH31-131-2 CH2CCHOMe32-132-2 CH2CCHOEt33-133-2 34-1 O-i-PrCH2CCH CH2CCHO-n-Bu35-135-2 MeOAc36-136-2 MeCH2OMe37-137-2 MeCH2OEt38-138-2 MeO-i-Pr39-139-2 40-1 O-n-BuMe MeOCH2CF341-141-2

Table 5 Compounds of formula (XX) wherein R201 is cyano; R202 is S (O) CF3; R204 is N (R205) C (O) CR206R207R208; R207 and R208 =H; R211 is Cl, X1 is C-Cl, and R213 is CF3 or SFs. Compound Compound R205 R206 Number Number (R213=CF3)(R213=SF5) MeH1-31-4 2-3 2-4 Me OMe 3-3 3-4 Me OEt MeO-i-Pr4-34-4 5-3 5-4 Me 0-n-Bu 6-3 6-4 Et H 7-3 7-4 Et OMe 8-3 8-4 Et OEt 9-3 9-4 Et O-i-Pr 10-3 10-4 Et O-n-Bu 11-3 11-4 n-Pr H 12-3 12-4 n-Pr OMe 13-3 13-4 n-Pr OEt 14-3 14-4 n-Pr O-i-Pr 15-3 15-4 n-Pr O-n-Bu 16-3 16-4 i-Pr H 17-3 17-4 i-Pr OMe 18-3 18-4 i-Pr OEt 19-3 19-4 i-Pr O-i-Pr 20-3 20-4 i-Pr O-n-Bu 21-3 21-4 n-Bu H 22-3 22-4 n-Bu OMe 23-3 23-4 n-Bu OEt 24-3 24-4 n-Bu O-i-Pr 25-3 25-4 n-Bu 0-n-Bu CH2CyH26-326-4 CH2CyOMe27-327-4 28-3 28-4 CHZCy OEt CH2CyO-i-Pr29-329-4 CH2CyO-n-Bu30-330-4 CH2CCHH31-331-4 CH2CCHOMe32-332-4 CH2CCHOEt33-333-4 34-3 34-4 CH2CCH 0-i-Pr 35-3 35-4 CH2CCH 0-n-Bu 36-3 36-4 Me OAc MeCH2OMe37-337-4 38-3 CH2OEtMe 39-3 39-4 Me O-i-Pr 40-3 40-4 Me 6-n-Bu 41-3 41-4 Me OCH2CF3 Compound 3-3 was separated into its enantiomers R3-3 and S3-3 Table 6 Compounds of formula (XX) wherein R201 is cyano; R202 is S (O) 2CF3; R204 is N (R205) C (O) CR206R207R208; ; R207 and R208 = H; R211 is Cl, X1 is C-Cl, and R213 is CF3 or SF5. Compound Compound R205 R206 Number Number (R213=SF5)(R213=CF3) MeH1-51-6 2-5 2-6 Me OMe 3-5 3-6 Me OEt 4-5 4-6 Me O-i-Pr 5-5 5-6 Me 0-n-Bu 6-5 6-6 Et 7-5 7-6 Et OMe 8-5 8-6 Et OEt EtO-i-Pr9-59-6 10-5 10-6 Et 0-n-Bu 11-5 11-6 n-Pr H 12-5 12-6 n-Pr OMe 13-5 13-6 n-Pr OEt 14-5 14-6 n-Pr O-i-Pr 15-5 15-6 n-Pr O-n-Bu i-PrH16-516-6 17-5 17-6 i-Pr OMe i-PrOEt18-518-6 i-PrO-i-Pr19-519-6 20-5 20-6 i-Pr O-n-Bu 21-5 21-6 n-Bu H 22-5 22-6 n-Bu OMe 23-5 23-6 n-Bu OEt 24-5 24-6 n-Bu O-i-Pr 25-5 25-6 n-Bu 0-n-Bu CH2CyH26-526-6 CH2CyOMe27-527-6 CH2CyOEt28-528-6 CH2CyO-i-Pr29-529-6 30-5 30-6 CH2Cy O-n-Bu CH2CCHH31-531-6 CH2CCHOMe32-532-6 33-5 33-6 CH2CCH OEt CH2CCHO-i-Pr34-534-6 35-5 35-6 CH2CCH 0-n-Bu 36-5 36-6 Me OAc 37-5 37-6 Me CH2OMe MeCH2OEt38-538-6 39-5 39-6 Me O-i-Pr 40-5 40-6 Me O-n-Bu MeOCH2CF341-541-6

Table 7 Compounds of formula (XX) wherein R201 is cyano; R202 is SCF3; R204 is N (R205) C (O) CR206R207R208; R211 is Cl; X1 is C-Cl; and R213 is CF3 or SFs- R205R206R207,R208CompoundCompound NumberNumber (R213=SF5)(R213=CF3) MeH-CH2CH2CH2O-1-71-8 EtH-CH2CH2CH2O-2-72-8 i-PrH-CH2CH2CH2O-3-73-8 PrH-CH2CH2CH2O-4-74-8 BuH-CH2CH2CH2O-5-75-8 CyH-CH2CH2CH2O-6-76-8 7-7 H-CH2CH2CH2O-CH2Cy Compound 1-7 was also separated into its enantiomers, called (R) 1-7 and (S) 1-7.

Compounds of formula (XX) wherein R201 is cyano; R202 is S (O) CF3; R204 is N (R205) C (O) CR206R207R208; R211 is Cl, X1 is C- Cl; and R213 is CF3 or SFs. R205R206R207,R208CompoundCompound NumberNumber (R213=CF3)(R213=SF5) MeH-CH2CH2CH2O-1-91-10 EtH-CH2CH2CH2O-2-92-10 i-PrH-CH2CH2CH2O-3-93-10 PrH-CH2CH2CH2O-4-94-10 BuH-CH2CH2CH2O-5-95-10 CH2CyH-CH2CH2CH2O-6-96-10 CyH-CH2CH2CH2O-7-97-10 Compound 1-9 was separated into its diastereomers, (R, R) 1-9, (S, R) 1-9, (S, S) 1-9, (R, S) 1-9. The first designation of absolute configuration refers to the configuration of the sulfoxide moiety, the second to the chiral carbon.

Table 9 Compounds of formula (XX) wherein R201 is cyano; R202 is S (0) 2CF3; R204 is N (R205) C (O) CR206R207R208; R211 is Cl; XI is C-Cl; and R213 is CF3 or SFs- R205R206R207,R208CompoundCompound NumberNumber (R213=CF3)(R213=SF5) 1-11 H-CH2CH2CH2O-Me 2-11 H-CH2CH2CH2O-Et i-PrH-CH2CH2CH2O-3-113-12A PrH-CH2CH2CH2O-4-114-12A BuH-CH2CH2CH2O-5-115-12A CyH-CH2CH2CH2O-6-116-12A CH2CyH-CH2CH2CH2O-7-117-12A

Compound 1-11 was also separated into its diastereomers, (R) 1-11 and (S) 1-11.

Table 10 Compounds of formula (XX) wherein R201 is cyano; R204 is N (R205) C (O) CR206R207R208; R207 and R208 are H; R211 is Cl, XI is C-Cl; and R213 is CF3 or SFs. Compound Compound R205 R206 Number Number (R213=CF3)(R213=SF5) R202=SCF3 1-12 1-13 Cy H 2-12 2-13 Cy OMe 3-12 3-13 Cy OEt 4-12 4-13 Cy i-O-Pr 5-12 5-13 Cy O-n-Bu R202=S(O)CF3 CyH6-126-13 7-12 7-13 Cy OMe CyOEt8-128-13 9-12 9-13 Cy O-i-Pr 10-12 10-13 Cy O-n-Bu R202=S(O)2CF3 11-12 11-13 Cy H 12-12 12-13 Cy OMe 13-12 13-13 Cy OEt 14-12 14-13 Cy O-i-Pr 15-12 15-13 Cy O-n-Bu

Table 11 Compounds of formula (XX) wherein R201 is cyano; R204 is -N (R205) C (O) OR207 ; R211 is Cl; X1 is C-Cl, and R213 is CF3 or SF5. Compound Compound R205 R207 Number Number (R213=SF5)(R213=CF3) R202 is SCF3 67-1 67-2 Me Me 68-1 68-2 Me Et 69-1 69-2 Me i-Pr 70-1 70-2 Me n-Pr EtMe71-171-2 72-1 72-2 Et Et Eti-Pr73-173-2 74-1 74-2 Et n-Pr 75-1 75-2 n-Pr Me 76-1 76-2 n-Pr Et n-Pri-Pr77-177-2 78-1 78-2 n-Pr n-Pr 79-1 79-2 i-Pr Me 80-1 80-2 i-Pr Et i-Pri-Pr81-181-2 82-1 82-2 i-Pr n-Pr R202 is S (O) CF3 83-1 83-2 Me Me 84-1 84-2 Me Et 85-1 85-2 Me i-Pr 86-1 86-2 Me n-Pr 87-1 87-2 Et Me 88-1 88-2 Et Et Eti-Pr89-189-2 90-1 90-2 Et n-Pr 91-1 91-2 n-Pr Me 92-1 92-2 n-Pr Et 93-1 93-2 n-Pr i-Pr 94-1 94-2 n-Pr n-Pr 95-1 95-2 i-Pr Me i-PrEt96-196-2 97-1 97-2 i-Pr i-Pr 98-1 98-2 i-Pr n-Pr R202 is S (0) 2CF3 99-1 99-2 Me Me 100-1 100-2 Me Et 101-1 101-2 Me i-Pr 102-1 102-2 Me n-Pr 103-1 103-2 Et Me 104-1 104-2 Et Et 105-1 105-2 Et i-Pr 106-1 106-2 Et n-Pr 107-1 107-2 n-Pr Me 108-1 108-2 n-Pr Et 109-1 109-2 n-Pr i-Pr 110-1 110-2 n-Pr n-Pr 111-1 111-2 i-Pr Me 112-1 112-2 i-Pr Et 113-1 113-2 i-Pr i-Pr 114-1 114-2 i-Pr n-Pr

Table 12 Compounds of formula (XX) wherein R201 is cyano; R202 is S (O) hCF3; R204 is N (R205) C (O) CR206R207R208; R211 is Cl ; Xi is C-Cl, and R213 is CF3 or SF5. hR205R206R207R208CompoundCompound Number Number (R213=SF5)(R213=CF3) 115-1 115-2 0 Me H Me Me 116-1 116-2 0 Me OEt H Me 117-1 117-2 0 Me H cyclopropyl 118-1 118-2 0 Me OMe H Me 119-1 119-2 0 Me OEt Me Me 2MeOCH2CH2OMeHH120-1120-2 121-1 121-2 0 Me H-CH2CH2CH2CH20- 122-1 122-2 1 Me OEt H Me 123-1 123-2 0 Me H H Me 124-1 124-2 0 Me H H Et

Table 13 Compounds of formula (XX) wherein R201 is cyano; R202 is S (O) hCF3; R204 is N (R205) C (O) aryl; R211 is Cl; X1 is C-CI, R205 is CH3; and R213 is CF3 or SFs. Within this table the following symbols are defined: Ph means phenyl; Fu means furyl Th means the thiophene radical Pyr means pyridyl Compound Compound aryl Number Number (R213=SF5)(R213=CF3) R202 is SCF3 125-1 125-2 Ph 126-1 126-2 4-OMe-Ph 4-CF3-Ph127-1127-2 128-1 128-2 2-Th 129-1 129-2 3-Th 130-1 130-2 2-Fu 131-1 131-2 3-Fu 132-1 132-2 2-Pyr 133-1 133-2 3-Pyr 134-1 134-2 4-Pyr 6-Cl-2-Pyr135-1135-2 136-1 136-2 6-CF3-2-Pyr 137-1 137-2 5-CI-2-Fu 138-1 138-2 5-CF3-2-Fu 139-1 139-2 5-OMe-2-Th 140-1 140-2 5-CF,-2-Th S(O)CF3R202is 125-3 125-4 Ph 126-3 126-4 4-OMe-Ph 4-CF3-Ph127-3127-4 128-3 128-4 2-Th 129-3 129-4 3-Th 130-3 130-4 2-Fu 131-3 131-4 3-Fu 132-3 132-4 2-Pyr 133-3 133-4 3-Pyr 134-3 134-4 4-Pyr 135-3 135-4 6-CI-2-Pyr 136-3 136-4 6-CF,-2-Pyr 5-Cl-2-Fu137-3137-4 138-3 138-4 5-CF3-2-Fu 5-OMe-2-Th139-3139-4 140-3 140-4 5-CF3-2-Th R202 is S(O)2CF3 125-5 125-6 Ph 126-5 126-6 4-OMe-Ph 4-CF3-Ph127-5127-6 128-5 128-6 2-Th 129-5 129-6 3-Th 130-5 130-6 2-Fu 131-5 131-6 3-Fu 132-5 132-6 2-Pyr 133-5 133-6 3-Pyr 134-5 134-6 4-Pyr 135-5 135-6 6-CI-2-Pyr 136-5 136-6 6-CF3-2-Pyr 137-5 137-6 5-CI-2-Fu 138-5 138-6 5-CF3-2-Fu 139-5 139-6 5-OMe-2-Th 140-5 140-6 5-CF3-2-Th

The present invention also relates to a composition comprising a parasiticidally effective, substantially non-emetic amount of a compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof and an acceptable carrier. Acceptable carriers for the use of the compounds are generally known to the skilled addressee concerned with pest control in animals, particularly domestic animals, most preferably dogs or cats.

The compositions which can be used in the invention can comprise generally from about 0.001 to 95% of the compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof. The remainder of the composition up to 100% comprises a carrier as well as generally various additives. In this specification and the accompanying claims, percentages are by weight.

The diluted liquid formulations generally comprise from about 0.001 to about 3% of compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof, preferably from about 0.1 to about 0.5%.

Solid formulations generally comprise from about 0.1 to about 8% of compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof, preferably from about 0.5 to about 1.5%.

Compositions for oral administration comprise one or more of the compounds of general formula (I) or salts thereof or compounds of formula (XX) or salts thereof in association with veterinarily acceptable carriers or coatings and include, for example, tablets, pills, capsules, gels, drenches, medicated feeds, medicated drinking water, medicated dietary supplements, slow-release boluses or other slow-release devices intended to be retained within the gastro-intestinal tract. Any of these may incorporate the active ingredients contained within micro-capsules or coated with acid-labile or alkali-labile or other pharmaceutically acceptable enteric coatings. Feed premixes or concentrates containing

compounds of the present invention for use in preparation of medicated diets, drinking water or other materials for consumption by animals may also be used. In a highly preferred embodiment, the compositions are administered postprandially, preferably from just after a meal to 2 hours after the meal.

In a highly preferred embodiment, there is provided a product which is readily chewed by the animal and which product does generally not allow human contamination when the product is provided to the animal by hand.

The compounds of general formula (I) or salts thereof or compounds of formula (XX) or salts thereof may be administered before, during or after meals The compounds of general formula (I) or salts thereof or compounds of formula (XX) or salts thereof may be mixed with a carrier and/or a foodstuff.

According to the present invention the compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof is administered orally in a dose to the animal in a dose range generally from 0.1 to 500 mg/kg of the compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof per kilogram of animal body weight (mg/kg), preferably from 1 to 100 mg/kg, more preferably from 1 to 50 mg/kg, even more preferably from 2 to 25 mg/kg, most preferably from 3 to 15 mg/kg According to the present invention, the frequency of treatment of the animal, preferably the domestic animal to be treated by the compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof is generally from about once per week to about once per year, preferably from about once every two weeks to about once every six months, more preferably from about once every two weeks to once every three months, and most preferably from about once every two weeks to about once every six weeks.

Generally the animal to be treated is a domestic animal, preferably a domestic companion animal. More preferably the animal to be treated is a dog and/or a cat.

The compounds of the invention may be administered most advantageously with another parasiticidally effective material, such as an endoparasiticide, and/or an ectoparasiticide, and/or an endectoparasiticide. For example, such compounds include macrocyclic lactones such as avermectins or milbemycins e. g., ivermectin; pyratel (generally adminsitered as pyrantel pamoate) or an insect growth regulator such as lufenuron or methoprene.

By the term"parasites"as used in the specification and claims is meant endoparasites and ectoparasites of warm-blooded animals, particularly ectoparasites. Preferably, fleas and/or ticks are controlled by the method of the present invention.

Illustrative of specific parasites of various host animals which may be controlled by the method of this invention include arthropods such as: Mites: Mesostigmata spp. e. g. mesostigmatids such as the chicken mite, Dermanyssus gallinae; itch or scab mites such as Sarcoptidae spp. for example Sarcoptes scabiei: mange mites such as Psoroptidae spp. including Chorioptes bovis and Psoroptes ovis ; chiggers e. g.

Trombiculidae spp. for example the north american chigger, Trombicula alfreddugesi; Ticks: e. g., soft-bodied ticks including Argasidae spp. for example Argas spp. and Ornithodoros spp; hard-bodied ticks including Ixodidae spp., for example Rhipicephalus sanguineus, and Boophilus spp.; Lice: sucking lice, e. g., Menopon spp. and Bovicola spp.; biting lice, e. g., Haematopinus spp., Linognathus spp. and Solenopotes spp.; Fleas: e. g., Ctenocephalides spp., such as dog flea (Ctenocephalides and cat flea (Ctenocephalides felis); Xenopsvlla

spp. such as oriental rat flea [Xenopsylla cheopis]; and Pulex spp. such as human flea [Pulex irritans]; True bugs: e. g., Cimicidae or including the common bed bug (Cimex lectularius);, Triatominae spp. including triatomid bugs also known as kissing bugs; for example Rhodnius prolixus and Triatoma bloodsucking adult flies: (e. g., horn fly [Haematobia irritans], horse fly [Tabanus spp.], stable fly [Stomoxys calcitrans], black fly [Simulium spp.], deer fly [Chrysops spp.], louse fly [Melophagus ovinus], tsetse fly [Glossina spp.], mosquitoes [Culex spp., Anopheles spp., and Aedes spp.); and parasitic fly maggots: (e. g., bot fly [Oestrus ovis and Cuterebra spp.], blow fly [Phaenicia spp.], screwworm [Cochliomvia hominivorax], cattle grub [Hypoderma spp.], fleeceworm.

The present invention also relates to a use of a compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof hereinbefore described as a therapeutic agent, preferably for animals, more preferably for domestic animals.

The veterinary composition may be sterile or non-sterile. It may be a liquid (e. g. aqueous) or solid (e. g., dry) composition, in particular a freeze-dried composition, which, by addition of water or another liquid, orally effective solutions may be prepared.

The present invention also relates to a use of a compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof as hereinbefore defined for the manufacture of a veterinary composition for the control of parasites in or on an animal.

The present invention also relates to a method of cleaning animals in good health comprising the application to the animal of a

compound of formula (I) or a salt thereof or a compound of formula (XX) or a salt thereof as hereinbefore defined to the animal.

The method of cleaning an animal is not a method of treatment by therapy of the animal body per se, because (a) the animal is in good health and requires no substantial treatment to correct a deficiency of health; (b) the cleaning of the animal is not intended to be done by veterinary personnel, but by persons interested in the cleaning of the animal; and (c) the purpose of such cleaning is to avoid unpleasant conditions for humans and the environment in which humans inhabit so as to not infest the said humans with arthropods carried by the animal.

By"carrier"is meant an organic or inorganic material, which can be natural or synthetic, and which is associated with the compound and which facilitates its application to the animal. This carrier is thus generally inert and should be arthropocidally acceptable. The carrier can be solid (e. g., clay, silicates, silica, resins, wax.) or liquid (e. g., water, alcohols, ketones, oil solvents, polar aprotic solvents) An example of an oil solvent is corn oil. An example of a polar aprotic solvent is dimethyl sulfoxide.

INCORPORERThe compounds of formula (II) wherein R21, R22, R24, R31, R33 and X are as defined above may be prepared from the compounds of formula (III):

(III) wherein R21, R22, R31, R33 and X are as defined above, using processes described in European Patent Publications 0511845 or 0659745.

According to a feature of the present invention, compounds of formula (II) wherein R21, R22, R31, R33 and X are as defined above and R24 is-N=C (R25)-NR26R27 wherein R25, R26 and R27 are as defined above may be prepared by reacting a compound of formula (III) with a compound of formula (IV): wherein R25, R26 and R27 are as defined above and R1oo is generally an alkyl group. The reaction is optionally conducted in the presence of a catalyst such as a mineral or organic acid (for example hydrochloric acid), generally using from 1 to 100 equivalents of (IV), preferably using 1 to 10 equivalents of (IV), and is preferably conducted in an organic solvent such as tetrahydrofuran, toluene, or N, N- dimethylformamide, at a temperature of from 0°C to 150°C. Additional adjuvants such as drying agents (e. g. magnesium sulfate, potassium carbonate, or molecular sieves) may also be advantageous to the reaction. Compounds of formula (IV) are known or may be prepared by known procedures.

According to a feature of the present invention, compounds of formula (II) wherein R21, R22, R31, R33 and X are as defined above and R24 is-N=C (R25)-NR26R27 wherein R25, R26 and R27 are as defined above, may be prepared by the reaction of a compound of formula (V): wherein R21, R22, R25, R31, R33, X and R100 are as defined above, with a compound of formula (VI): wherein R26 and R27 are as defined above. The reaction is generally conducted using the same conditions as used for the preparation of compounds of formula (II) by the reaction of compounds of formula (III) with compounds of formula (IV).

According to a feature of the present invention, compounds of formula (II) wherein R24 is-N=C (R25)-NR27R28 and R21, R22, R25, R27, R31 R33 and X are as defined above, and R28 is COR34 wherein R34 is as defined above, may be prepared by the reaction of the corresponding compounds of formula (II) wherein R24 is-N=C (R25)- NR27H with an acid chloride of formula (VII): R34COCl (VII) wherein R34 is as defined above. The reaction is generally performed in the presence of a base such as a trialkylamine for example

triethylamine in a solvent such as dichloromethane, at a temperature of from 0°C to 50°C.

According to a feature of the present invention, compounds of formula (II) wherein R24 is-N=C (R25)-NR27R2g, and R21, R22, R25, R27, R31, R33 and X are as defined above and R28 is-S (O) tR30 may be prepared by the reaction of the corresponding compound of formula (II) wherein R24 is-N=C (R25)-NR2H with a sulfonyl chloride or a sulfenyl chloride of formula (VIII): R30S (O) tCl (VIII) The reaction is generally performed in the presence of a weak base such as a trialkylamine for example triethylamine, or pyridine in a solvent such as dichloromethane, at a temperature of from 0°C to 50°C.

Compounds of formula (VI), (VII) and (VIII) are known or may be prepared by known procedures.

Compounds of formula (III) and (V) may be generally prepared according to known processes, for example as described in International Patent Publications WO 87/3781, WO 93/6089, WO 94/21606 WO 97/07102, WO 98/24767,, WO 98/28277, WO 98/28278 and WO 98/28279,, European Patent Application 295117,846686, and United States Patent 5232940..

In another aspect of the present invention, compounds of formula (XX) wherein R204 is-N (R205) C (O) CR206R207R208 N (R205) C (O) aryl, or N (R205) C (O) OR207 are generally prepared from compounds of formula (XXI):

respectively by reaction with halides of formulae X2C (O) CR206R207R208, X2C (O) aryl, or X2C (O) OR207, wherein R201, R202, R205, R206, R207, R208, R211, R213, and XI are defined above and wherein X2 is a halogen atom. The reaction is generally carried ouT in the presence of a base, generally using from 1 to 10 molar equivalents of the halide, and is preferably conducted in the presence of an organic solvent such as tetrahydrofuran, methylene chloride, at a temperature of from 0°C to 150°C.

Compounds of formula (XXI) may be prepared from a compound of formula (XXII):

(XXII) by reaction with a compound of formula (XXIII): X2R205 (XXIII) wherein R201, R202, R205, R211, R213, XI and X2 are defined above. Compounds of formula (XXIII) are generally known in the art as alkylhalides or substituted alkylhalides. Compounds of formula XXII may be prepared by methods described in International Patent Publications WO 87/3781, WO 93/6089, WO 94/21606, WO 97/07102, WO 98/24767,, WO 98/28277, WO 98/28278 and WO 98/28279, European Patent Application 295117,659745,846686, and United States Patent 5232940 or other methods known to the person skilled in the art.

Alternatively compounds of formula (XXI) may be prepared by reduction of compounds of formula (XXIV): wherein R201 R202, R211, R213 and X1 are defined above. The reduction generally is effected by the use of a standard hydride ion donor, for example sodium borohydride or sodium cyanoborohydride.

The reaction is generally effected in an polar solvent such as ethanol or

methanol and generally using from 1 to 10 molar equivalents of the hydride, and is preferably conducted at temperature of from-100°C to 150°C.

Compounds of formula (XXIV) may be prepared using methods described in EP 295117, WO 97/22593 or other methods known to those skilled in the art.

In another aspect of the invention there are provided the compounds 3-Cyano-1- (2,6-dichloro-4-trifluoromethylphenyl)-5- ethoxymethylideneamino-4-trifluoromethylsulfinylpyrazole and 3- cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5-methylamino -4- trifluoromethylsulfinylpyrazole which are useful intermediates for the preparation of compounds for use according to the present invention.

Biological Example Compounds 1-1,2-1,3-1,4-1,11-1,13-1,28-1,31-1,32-1,36-1, <BR> <BR> <BR> 37-1,38-1,1-3,2-3,3-3,4-3,6-3,41-3,1-5,2-5,3-5,6-5,11-5,27-5 , <BR> <BR> <BR> <BR> 69-1,70-1,72-1,75-1,76-1,77-1,78-1,79-1,80-1,81-1,82-1,115-1 , 122-1,123-1,124-1,211-1, 219,220,221,222,223,224,225,226,227,228,229,230,231,232, 233, R3-3, S3-3, Rl-7, S1-7, (R, S) 1-9, (R, R) 1-9, (S, R) 1-9, (S, S) 1-9, Sl-11, R1-11,126-1,127-1 and 130-1 were formulated as a 30 mg/mL formulations in a 1: 1 volume/volume solution of dimethyl sulfoxide and corn oil. Using this formulation, mixed breed dogs and cats were treated at a rate of 10 mg of the compound per kg (mg/kg) of body weight of the dog and 20 mg/kg of the cat treated. The animals were fasted for at least 8 hours prior to treatment, fed half of the daily ration

immediately prior to treatment, then allowed access to the remainder of the daily ration immediately following treatment.

All dogs were infested with cat fleas (Ctenocephalides felis) and with ticks (Rhipicephalus sanguineus) 1 day prior to administration of the compound. Cats were only infested with fleas. The initial flea and tick counts were performed 1 day after the administration of the compounds. At 7,14,21 and 28 days after treatment the dogs were re- infested with ticks and 8,15,22 and 29 days after treatment the dogs and cats were re-infested with fleas. At 1,9,16,23 and 30 days after treatment the control of fleas and ticks in treated dogs and cats was determined versus a group of infested dogs and cats which received a placebo consisting of a 1: 1 volume/volume solution of dimethyl sulfoxide and corn oil. To determine the efficacies of the compounds, the arthropods were combed from the animals and counted.

In the animals treated with the compounds above, there was substantially no emesis after 2,8 and 24 hours. Generally long-term control of fleas and ticks was provided in dogs. In the cats treated, there was commercially acceptable control of fleas for at least one day post treatment.

The results of this example were superior to those obtained with compounds of the prior art, for example, fipronil.

The following non-limiting Synthesis Examples illustrate the preparation of compounds of formula (I) and the Reference Examples illustrate the preparation of intermediates used in their synthesis.

Svnthesis Example 1 A solution of 5-amino-3-cyano-1-(2,6-dichloro-4- trifluoromethylphenyl)-4-trifluoromethylthiopyrazole (1 g) in N, N- dimethylformamide dimethyl acetal was heated at 50°C for 1 hour.

Evaporation of solvents gave 3-cyano-1-(2,6-dichloro-4- trifluoromethylphenyl)-5-N'-dimethylaminomethylideneamino-4- trifluoromethylthiopyrazole m. p. 141 °C.

By proceeding in a similar manner the following compounds were also prepared: <BR> <BR> <BR> <BR> 3-cyano-1- (2,6-dichloro-4-trifluoromethylphenyl)-5-N'-<BR> <BR> <BR> <BR> <BR> <BR> <BR> dimethylaminomethylideneamino-4-trifluoromethylsulfonylpyraz ole m. p. 209°C; and <BR> <BR> <BR> <BR> 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5-N'-<BR > <BR> <BR> <BR> <BR> <BR> <BR> dimethylaminomethylideneamino-4-trifluoromethylsulfinylpyraz ole m. p. 207°C.

Svnthesis Example 2 A solution of 3-cyano-1- (2,6-dichloro-4- trifluoromethylphenyl)-5-ethoxymethylideneamino-4- trifluoromethylthiopyrazole (5 g) in ethanol was treated with benzylamine (11.4 ml), stirred overnight, evaporated and purified by reverse-phase column chromatography (C-18 stationary phase column, eluting with MeOH/water) to give 5-N'-benzylaminomethylideneamino- 3-cyano-1- (2, 6-dichloro-4-trifluoromethylphenyl)- 4- trifluoromethylthiopyrazole 1.18 g), m. p. ll3°C.

By proceeding in a similar manner the compounds of formula (II) wherein R21 is CN; R24 is-N=CH-NHR26; R31 is Cl; X is C-Cl; and R33 is CF3 shown in Table 4 were also prepared.

Table 4 Compd No. R22 R26 M. P. °C 21 SCF3 CH2CN 175 211-1 SCF3 CH2CF3 130 222 SCF3 CH3 173 223 SOCF3 CH2Ph 173 225 SOCF3 CH3 144 226 SOCF3 CH3 144 227 SOCF3 CH2CF3 175 228 S02CF3 2-propynyl 149 229 S02CF3 CH2Ph 182 230 S02CF3 CH2CF3 183 209-1 SCF3 iPr 207-1 SCF3 CH2CH3 141 Reference Example 1 A solution of 5-amino-3-cyano-1-(2,6-dichloro-4- trifluoromethylphenyl)-4-trifluoromethylthiopyrazole (500 g) in triethyl orthoformate was treated with concentrated hydrochloric acid (10 ml) and heated at 50°C. After 8 hours the reaction mixture was evaporated to give a solid which was washed (heptane) and air-dried to give 3- cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5- ethoxymethylideneamino-4-trifluoromethylthiopyrazole (217 g), m. p.

68°C.

By proceeding in a similar manner the following intermediates were also prepared: 3-cyano-1- (2,6-dichloro-4-trifluoromethylphenyl)-5- ethoxymethylideneamino-4-trifluoromethylsulfinylpyrazole, m. p. 63°C; and 3-cyano-1- (2,6-dichloro-4-trifluoromethylphenyl)-5- ethoxymethylideneamino-4-trifluoromethylsulfonylpyrazole, m. p. 118°C.

Svnthesis Example 3 3-Cyano-1-(2, 6-dichloro-4-trifluoromethylphenyl)-5- methylamino-4-trifluoromethylsulfmylpyrazole (111.55 g, 0.247 moles), triethylamine (62.45 g, 0.618 moles), 4-dimethylaminopyridine (3 g, 0.0247 moles), and tetrahydrofuran (700 ml) was combined. The resulting solution was heated to 45°C and ethoxyacetyl chloride (45.2 g,

0.37 mmol) was added dropwise over 10 min. After 1 h, the mixture was evaporated to a brown residue, which was dissolved in 500 ml of ethyl acetate and washed with 2 x 300 ml of water. The organic phase was dried over magnesium sulfate, filtered, and evaporated to a brown oil. The oil was triturated with 1 L of hot cyclohexane. The resulting solids were collected by filtration and washed with 500 ml of hot cyclohexane, then air dried to afford of compound 3-3 as a beige powder (116.7 g). Evaporation of the mother liquors afforded a second crop of compound 3-3 (8.4 g).

In a similar fashion or by modifications according to methods known to the skilled addressee, the following compounds were prepared. The compound numbers in the left column refer to the Tables cited above. Compound Mass Spectral Number molecular ion + 1 (M+1) 1-1 477 2-1 507 3-1 521 4-1 535 11-1 505 13-1 549 28-1 537 31-1 517 32-1 531 36-1 535 37-1 521 38-1 535 1-3 593 2-3 523 3-3 537 4-3 551 6-3 491 41-3 473 1-5 509 2-5 539 3-5 553 6-5 523 11-5 537 27-5 579 28-5 593 1-7 533 3-7 561 5-7 575 1-9 549 1-11 565 6-11 591 7-11 605 1-12 535 11-12 565 13-12 579 67-1 493 68-1 507 69-1 521 70-1 521 72-1 521 75-1 521 76-1 535 77-1 549 78-1 549 79-1 521 80-1 535 81-1 549 82-1 549 115-1 505 116-1 535 117-1 503 118-1 521 119-1 549 120-1 583 121-1 547 122-1 551 123-1 491 124-1 505 126-1 507 127-1 607 130-1 529 Reference Example 2: Step A: Preparation of 3-Cyano-1- (2,6-dichloro-4- trifluoromethylphenyl)-5-ethoxymethylideneamino-4- trifluoromethylsulfinylpyrazole.

A 12-L three-necked flask fitted with an overhead stirrer, heating mantle, water separator (e. g. Dean Stark trap) with condenser was placed under a nitrogen atmosphere and charged with 1.475 kg (3.37 moles) of fipronil and 6 L of triethyl orthoformate. The suspension was

heated to reflux over 2.5 h, then at reflux for 3 h with collection and removal of the distillate. The mixture was cooled to room temperature, then evaporated under reduced pressure at a bath temperature of 60- 80°C, then at 50°C overnight. The resulting beige solid, 1.717 kg (95.8 % by HPLC, 3.335 moles, 99% purity corrected yield) was used without further purification. (m. p. about 63°C) Step B: Preparation of 3-Cyano-1-(2,6-dichloro-4- trifluoromethylphenyl)-5-methylamino-4- trifluoromethylsulfinylpyrazole.

A 50 L reactor was charged with 3-Cyano-1-(2,6-dichloro-4- trifluoromethylphenyl)-5-ethoxymethylideneamino-4- trifluoromethylsulfinylpyrazole (1.645 g, 3.335 moles) and absolute ethanol (16 L) under nitrogen. The solution was cooled to 10°C, and sodium borohydride (266 g, 7.03 moles) was added slowly such that the temperature, remained generally below 35°C. After 6.75 h, some additional sodium borohydride (25 g, 0.66 moles) was added and stirring was continued overnight. Acetic acid (1.3 L, 22.7 moles) was added to quench, followed by 16 L of water. The resulting precipitate was collected by filtration, washed with water, and air-dried.

Recrystallization from methanol afforded 3-Cyano-1- (2,6-dichloro-4- trifluoromethylphenyl)-5-methylamino-4- trifluoromethylsulfinylpyrazole (350 g) as an off-white solid. (m. p. about 227°C)