Processes for the preparation of pesticidal compounds

Patent metadata

Field	Value
Publication number	US-9723839-B2
Application number	US-201615223055-A
Country	US
Kind code	B2
Filing date	Jul 29, 2016
Priority date	Oct 17, 2013
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

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

First claim

What is claimed is:

1. A process comprising:
(a) halogenating and reducing 4-nitropyrazole

with concentrated hydrochloric acid at a temperature between about 10° C. and about 20° C. with between about 1 equivalent and about 4 equivalents of triethylsilane and about 1 to 10 weight percent palladium on alumina to yield 3-chloro-1H-pyrazol-4-amine hydrochloride (1a)

(b) acylating 1(a) with 3-chloropropionyl chloride in the presence of a base to yield 3-chloro-N—(-3-chloro-1H-pyrazol-4-yl)propanamide (4a)

(c) reacting (4a) with HS—R 1 in the presence of a base wherein R 1 is selected form the group consisting of C 1 -C 4 haloalkyl and C 1 -C 4 alkyl-C 3 -C 6 halocycloalkyl to yield pesticidal thioethers (4b),

(d) heteroarylation of (4b) with a halopyridine in the presence of a copper salt, an amine, and a base, to yield thioether (4c)

(e) alkylating a thioether (4c) with R 2 —X 2 in the presence of a base wherein R 2 is selected from the group consisting of C 1 -C 4 -alkyl and C 2 -C 4 -alkynyl, and wherein X 2 is a leaving group, to yield thioether (4d)

2. The process according to claim 1 wherein R 1 is C 1 -C 4 haloalkyl.

3. The process according to claim 1 wherein R 1 is CH 2 CH 2 CF 3 .

4. The process according to claim 1 wherein R 1 is C 1 -C 4 alkyl-C 3 -C 6 halocycloalkyl.

5. The process according to claim 1 wherein R 1 is CH 2 (2,2-difluorocyclopropyl).

6. The process according to claim 1 , wherein thioether (4d)

is prepared by alkylating thioether (4c) with R 2 —X 2

wherein R 2 is selected from the group consisting of C 1 -C 4 -alkyl and C 2 -C 4 -alkynyl, wherein X 2 is a leaving group, in the presence of a base, in the presence of a polar aprotic solvent, and in the presence of an additive.

7. The process of claim 1 , wherein the base in step (b) is a metal carbonate, a metal hydroxide or a metal phosphate.

8. The process of claim 1 , wherein the base in step (b) is a NaHCO 3 .

9. The process of claim 1 , wherein step (b) is carried out in the presence of a mixture of tetrahydrofuran and water.

10. The process of claim 1 , wherein the base in step (c) is a metal carbonate, a metal hydroxide, a metal phosphate or metal hydride.

11. The process of claim 1 , wherein the base in step (c) is potassium hydroxide.

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

13. The process of claim 1 , wherein step (c) is carried out in the presence of methanol.

14. The process of claim 1 , wherein the halopyridine in step (d) is 3-bromopyridine.

15. The process of claim 1 , wherein the copper salt in step (d) is copper(I) chloride (CuCl), copper(II) chloride (CuCl 2 ) or copper(I) iodide (CuI).

16. The process of claim 1 , wherein the amine in step (d) is N,N′-dimethylethane-1,2-diamine.

17. The process of claim 1 , wherein the base in step (d) is potassium phosphate or potassium carbonate.

18. The process of claim 1 , wherein R 2 —X 2 in step (e) is selected from the group consisting of methyl iodide, ethyl bromide, ethyl iodide, propargyl chloride, propargyl bromide, ethyl mesylate, propargyl mesylate, ethyl tosylate, and propargyl tosylate.

19. The process of claim 1 , wherein base in step (e) is a metal carbonate, a metal hydroxides, a metal phosphate or metal hydride.

20. The process of claim 1 , wherein base in step (e) is cesium carbonate.

Assignees

• Dow Agrosciences Llc

Inventors

• Yang Qiang
• Lorsbach Beth
• Whiteker Gregory
• Deamicis Carl
• Muhuhi Joseck M

Classifications

• C07D231/38

  Nitrogen atoms (nitro radicals C07D231/16) · CPC title

• C07D231/40

  Acylated on said nitrogen atom · CPC title

• A01N43/56 Primary

  1,2-Diazoles; Hydrogenated 1,2-diazoles · CPC title

• C07D401/04

  directly linked by a ring-member-to-ring-member bond · CPC title

• Y10S424/10

  Insect repellent · CPC title