Method for producing 2,3-dichloro-5-(trichloromethyl)pyridine

• US 9,809,543 B2
• Filed: 06/13/2014
• Issued: 11/07/2017
• Est. Priority Date: 06/14/2013
• Status: Active Grant

• Current Assignee: Cheminova A/S (FMC Corporation)
• Original Assignee: Cheminova A/S (FMC Corporation)
• Inventors: Andersen, Casper Stoubaek
• Primary Examiner(s): Jarrell, Noble
• Assistant Examiner(s): Kenyon, John S
• Application Number:
  US14/898,416
• Publication Number:
  US 20160145211A1
• Time in Patent Office: 1,243 Days
• CPC Class Codes: C07D 213/61 Halogen atoms or nitro radicals
• CPC Class Codes: C07D 213/643 2-Phenoxypyridines; Derivatives thereof
• CPC Class Codes: C07D 213/74 Amino or imino radicals substituted by hydrocarbon or substituted hydrocarbon radicals

Abstract

The present invention relates to a novel process for producing of 2,3-dichloro-5-(trichloromethyl)pyridine by using PCl as chlorinating agent at elevated temperature and pressure.

Claims

1. A method for preparing 2,3-dichloro-5-(trichloromethyl)pyridine of formula [II] by a process which comprises the steps:

(1) preparing a reaction mixture comprising a compound of the general formula [I] and PCl₅,

2. The method according to claim 1, wherein the reaction mixture further comprises at least one additional chlorinating agent selected from the group consisting of Cl₂, PCl₃, SOCl₂, COCl₂, (COCl)₂, and POCl₃.

3. The method according to claim 2, wherein the additional chlorinating agent is Cl₂.

4. The method of claim 1, wherein X is COOH.

5. The method according to claim 1, wherein the temperature of the reaction is in the range between 70°

C. to 200°

C.

6. The method according to claim 1, wherein the temperature of the reaction is above 160°

C.

7. The method according to claim 1, wherein the pressure of the reaction is above 2 bar.

8. The method according to claim 1, wherein the pressure of the reaction is below 50 bar.

9. The method according to claim 1, wherein the pressure of the reaction is in the range of 2 to 30 bar.

10. The method according to claim 1, wherein the pressure of the reaction is above 30 bar.

11. The method according to claim 1, wherein the temperature of the reaction is in the range of 160°

C. to 250°

C., and the pressure of the reaction is in the range of 10 bar to 30 bar.

12. The method according to claim 1, wherein the reaction is conducted in the absence of solvent.

13. The method according to claim 1, wherein the reaction is conducted in the presence of a solvent.

14. The method according to claim 13, wherein the solvent is a chlorinated solvent.

15. The method according to claim 13, wherein the solvent is phosphorous trichloride, phosphoryl chloride, monochlorobenzene, dichlorobenzene, chlorotoluene, chloronaphthalene, methylene dichloride, ethylene dichloride, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, or mixtures thereof.

16. The method according to claim 1, wherein the PCl₅ is generated in-situ, in part or in total.

17. The method according to claim 16, wherein the PCl₅ is generated from a reaction between PCl₅ and Cl₂.

18. The method according to claim 17, wherein Cl₂ is used in equimolar amounts or less in respect of the PCl₃.

19. The method according to claim 1, wherein the total amount of chlorinating agent is between 2 to 15 moles per mole of the compound of the general formula W.

20. The method according to claim 1, further comprising a second chlorination step whereby any amount of the intermediate compound (A) formed in the process is further chlorinated to produce the compound of formula [II].

21. The method according to claim 20, wherein Cl₂ is added in the second chlorination step to produce the compound of formula [II].

22. The method according to claim 20, wherein PCl₅, if present, is removed from the reaction mixture prior to the secondary chlorination.

23. The method according to claim 20, wherein a catalyst is provided to promote the secondary chlorination.

24. The method according to claim 23, wherein the catalyst is selected from the group consisting of:

metal chlorides, oxychlorides, carbonyls;

phosphines; and

boranes.

25. The method according to any of the claims 1 to 24 further comprising a fluorination step to fluorinate the compound of formula [II] to obtain the compound of formula [III]

26. The method according to claim 25, wherein the compound of formula [III] is further converted to a pesticidal active compound.

27. The method according to claim 26, wherein the pesticidal active compound is a herbicide, an insecticide or a fungicide.

28. The method according to claim 27 wherein the pesticidal active compound is fluazinam, fluopicolide, haloxyfop, chlorfluazuron or fluazuron.

29. The method according to claim 24 wherein the metal chloride catalyst is selected from the group consisting of:

FeCl₃;

AlCl₃;

SnCl₄;

WCl₆;

MoCl₅;

MoCl₄O; and

WCl₄O.

30. The method according to claim 24 wherein the carbonyl catalyst is selected from the group consisting of:

Mo(CO)₅;

W(CO)₆; and

mixtures thereof.

31. The method according to claim 24 wherein the phosphine catalyst is selected from the group consisting of:

(Ph)₃P;

(Ph)₃P═

O; and

mixtures thereof.

32. The method according to claim 24 wherein the borane catalyst is BCl₃.