Processes for the preparation of pesticidal compounds

• US 9,255,083 B2
• Filed: 05/21/2015
• Issued: 02/09/2016
• 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, Roth, Gary, Niyaz, Noormohamed M., Nissen, Jeffrey, Ross, Ronald Jr., Whiteker, Greg, DeAmicis, Carl, Gray, Kaitlyn, Zhang, Yu
• Primary Examiner(s): Morris, Patricia L
• Application Number:
  US14/718,627
• Publication Number:
  US 20150252018A1
• Time in Patent Office: 264 Days
• Field of Search: 546/275.4
• US Class Current: 1/1
• CPC Class Codes: A01N 43/40 six-membered rings
• CPC Class Codes: A01N 43/56 1,2-Diazoles; Hydrogenated 1,2-diazoles
• CPC Class Codes: C07D 213/77 Hydrazine radicals
• 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 comprising:

(a) reacting 3-hydrazinopyridine dihydrochloride with glyoxylic acid to yield (E)-2-(2-(pyridin-3-yl)hydrazono)acetic acid (6a)

2. The process of claim 1, wherein step (a) is carried out in the presence of an acid.

3. The process of claim 2, wherein the acid is hydrochloric acid.

4. The process of claim 1, wherein step (a) is carried out in the presence of a protic solvent.

5. The process of claim 1, wherein the source of chlorine in step (b) is N-chlorosuccinimide.

6. The process of claim 1, wherein the base in step (b) is an inorganic base selected from the group consisting of a metal carbonate, a metal hydroxide, a metal phosphate, or a metal hydride.

7. The process of claim 6, wherein the inorganic base is potassium bicarbonate.

8. The process of claim 1, wherein step (b) is carried out in the presence of a polar aprotic solvent.

9. The process of claim 1, wherein the base in step (c) is selected from the group consisting of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and potassium hydroxide.

10. The process of claim 1, wherein step (c) is carried out in the presence of a polar solvent.

11. The process of claim 10, wherein the polar solvent is N,N-dimethyl-formamide (DMF), ethanol (EtOH), or tetrahydrofuran (THF).

12. The process of claim 1, wherein step (d) is carried out in the presence of sulfuric acid.

13. The process of claim 1, wherein step (d) is carried out at a temperature of from about −

10°

C. to about 30°

C.

14. The process of claim 1, wherein step (e) is carried out using iron as the reducing agent.

15. The process of claim 14, wherein step (e) is carried out in the presence of acetic acid or ammonium chloride.

16. The process of claim 1, wherein step (e) is carried out using palladium on carbon in the presence of H₂ gas as the reducing agent.

17. The process of claim 1, wherein step (f) is carried out in the presence of sodium borohydride.

18. The process of claim 17, wherein step (f) is carried out in a polar protic solvent.

19. The process of claim 1, wherein R¹ is —

CH₂CH₂CF₃ or —

CH₂(2,2-difluorocyclopropyl).

20. The process of claim 1, wherein step (g) is carried out in the presence of sodium bicarbonate.