Process for the preparation of pesticidal compounds
View Patent ↗A process for the preparation of a compound of general formula (I), wherein R 1 is CN or CSNH 2 ; R 2 is hydrogen or chloride; and R 3 is halogen or haloalkyl or haloalkoxy or SF 5 which process comprises reacting a compound of formula (II), where R 1 , R 2 and R 3 are as defined above; with a proton source.
1. A process for the preparation of a compound of general formula (I)
wherein R 1 is CN or CSNH 2 ; R 2 is hydrogen or chloro; X is N or CR 4 ; R 4 is hydrogen or chloro; n is 0, 1 or 2; and R 3 is halo, haloalkyl, haloalkoxy or SF 5 ; which process comprises:
(i) reacting a compound of the formula (III)
wherein R 1 is CN or CSNH 2 ; R 2 is hydrogen or chloro; X is N or CR 4 ; R 4 is hydrogen or chloro; n is 0, 1 or 2; and R 3 is halo, haloalkyl, haloalkoxy or SF 5 ;
with a quaternary ammonium salt to form a compound of the formula (II):
wherein R 1 , R 2 , X, n and R 3 are as defined above; and
(ii) reacting a compound of the formula (II) with a proton source.
2. A process as claimed in claim 1 in which R 1 is CN, R 2 is chloro, R 4 is chloro, X is CCl, n is 1 and R 3 is trifluoromethyl.
3. A process as claimed in claim 1 in which the proton source is an aqueous acidic solution.
4. A process as claimed in claim 3 in which the aqueous acidic solution is aqueous hydrogen chloride.
5. A process as claimed in claim 1 in which the reaction is carried out in the presence of a solvent.
6. A process as claimed in claim 5 in which the solvent is toluene or xylene.
7. A process for the preparation of a compound of the formula (II)
which process comprises reacting a compound of the formula (III)
wherein R 1 is CN or CSNH 2 ; R 2 is hydrogen or chloro; X is N or CR 4 ; R 4 is hydrogen or chloro; n is 0, 1 or 2; and R 3 is halo, haloalkyl, haloalkoxy or SF 5 ; with a quaternary ammonium salt.
8. A process as claimed in claim 7 in which the quaternary ammonium salt is a tetraalkylammonium halide.
9. A process as claimed in claim 7 in which the tetraalkylammonium halide is tetraalkylammonium bromide.
10. A process as claimed in claim 7 in which the reaction is carried out in the presence of an organic solvent.
11. A process as claimed in claim 10 in which the solvent is toluene or xylene.
12. A process as claimed in claim 1 in which the quaternary ammonium salt is a tetraalkylammonium halide.
13. The compound 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5-N-formyl-N-methylamino-4-trifluoromethylsulfinylpyrazole.
14. The compound 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5-methoxy methylideneamino-4-trifluoromethylsulfinylpyrazole.
15. A process as claimed in claim 2 in which the proton source is an aqueous acidic solution.
16. A process as claimed in claim 15 in which the aqueous acidic solution is aqueous hydrogen chloride.
17. A process as claimed in claim 2 in which the reaction is carried our in the presence of a solvent.
18. A process as claimed in claim 17 in which the solvent is toluene or xylene.
19. A process as claimed in claim 3 in which the reaction is carried out in the presence of a solvent.
20. A process as claimed in claim 19 in which the solvent is toluene or xylene.
21. A process as claimed in claim 4 in which the reaction is carried out in the presence of a solvent.
22. A process as claimed in claim 21 in which the solvent is toluene or xylene.
23. A process as claimed in claim 15 in which the reaction is carried out in the presence of a solvent.
24. A process as claimed in claim 23 in which the solvent is toluene or xylene.
25. A process as claimed in claim 16 in which the reaction is carried out in the presence of a solvent.
26. A process as claimed in claim 25 in which the solvent is toluene or xylene.
27. A process as claimed in claim 12 in which the tetraalkylammonium halide is tetraalkylammonium bromide.
28. A process as claimed in claim 8 in which the reaction is carried out in the presence of an organic solvent.
29. A process as claimed in claim 28 in which the solvent is toluene or xylene.
30. A process as claimed in claim 9 in which the reaction is carried out in the presence of an organic solvent.
31. A process as claimed in claim 29 in which the solvent is toluene or xylene.
32. A process as claimed in claim 27 in which the reaction is carried out in the presence of an organic solvent.
33. A process as claimed in claim 32 in which the solvent is toluene or xylene.