Processes for the preparation of pesticidal compounds

• US 9,126,974 B2
• Filed: 03/24/2015
• Issued: 09/08/2015
• Est. Priority Date: 10/17/2013
• Status: Expired due to Fees

• Current Assignee: Dow Agrosciences LLC (Corteva, Inc.)
• Original Assignee: Dow Agrosciences LLC (Corteva, Inc.)
• Inventors: Yang, Qiang, Lorsbach, Beth, Ross, Ronald Jr., Gray, Kaitlyn, Zhang, Yu, Roth, Gary
• Primary Examiner(s): Rozof, Timothy R
• Application Number:
  US14/666,825
• Publication Number:
  US 20150191448A1
• Time in Patent Office: 168 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A01N 43/56 1,2-Diazoles; Hydrogenated 1,2-diazoles
• CPC Class Codes: C07C 319/18 by addition of thiols to unsaturated compounds
• CPC Class Codes: C07C 319/20 by reactions not involving the formation of sulfide groups
• CPC Class Codes: C07C 321/14 of an acyclic saturated carbon skeleton
• CPC Class Codes: C07D 231/38 Nitrogen atoms nitro radicals C07D231/16
• CPC Class Codes: C07D 231/40 Acylated on said nitrogen atom
• CPC Class Codes: C07D 401/04 directly linked by a ring-member-to-ring-member bond

Abstract

The present application provides processes for making pesticidal compounds and compounds useful both as pesticides and in the making of pesticidal compounds.

Claims

1. A process for the preparation of thioether (7b) useful as a pesticide,

2. The process according to claim 1, wherein R¹ is C₁-C₄ haloalkyl.

3. The process according to claim 2, wherein R is CH₂CH₂CF₃.

4. The process according to claim 1, wherein R¹ is —

C₁-C₄ alkyl-C₃-C₆ halocycloalkyl.

5. The process according to claim 4, wherein R¹ is

6. A process comprising:

(a) halogenating and reducing 4-nitropyrazole

7. The process according to claim 6, wherein step (a) is carried at a temperature between about 10°

C. and about 20°

C.

8. The process according to claim 6, wherein step (a) is carried out in a polar protic solvent.

9. The process according to claim 8, wherein step (a) is carried out in a polar protic solvent is methanol or ethanol.

10. The process according to claim 7, wherein step (a) is carried out with between about 2.5 and about 3.5 equivalents of triethylsilane.

11. The process according to claim 6, wherein the base in step (b) is sodium bicarbonate.

12. The process according to claim 6, wherein the temperature of step (b) is between about 0°

C. and about 40°

C.

13. The process according to claim 12, wherein the reducing agent in step (c) is sodium borohydride.

14. The process according to claim 12, wherein the Lewis acid in step (c) is borontrifluoride etherate.

15. The process according to claim 6, wherein the base in step (d) is sodium bicarbonate.

16. The process according to claim 15, wherein R¹ is CH₂CH₂CF₃.

17. The process according to claim 15, wherein R¹ is

18. The process according to claim 6, wherein the halopyridine in step (e) is 3-bromopyridine.

19. The process according to claim 18, wherein the copper salt of step (e) is copper (I) chloride, copper (II) chloride or copper (I) iodide.

20. The process according to claim 19, wherein the amine of step (e) is N,N′

-dimethylethane-1,2-diamine.

21. The process according to claim 20, wherein the base of step (e) is potassium carbonate.

22. The process according to claim 6, further comprising the step of contacting the thioether of the formula (1e)

23. The process of claim 22, wherein the oxidizing agent is hydrogen peroxide in methanol.