Processes for the preparation of pesticidal compounds

1. A process comprising:

(a) halogenating and reducing 4-nitropyrazole to produce

3-chloro-1H-pyrazol-4-amine hydrochloride (1a)

with concentrated hydrochloric acid at a temperature between about 10° C. and about 20° C. with between about 1 and about 4 equivalents of triethylsilane and about 1 to 10 weight percent palladium on alumina;

(b) mono-acylating 3-chloro-1H-pyrazol-4-amine hydrochloride (1a) with acetic anhydride in the presence of a base to yield

(c) reacting 1(b) with a suitable halopyridine in the presence of a copper salt, an amine, and a base, to yield N-(3-chloro-1-(pyridin-3-yl)-1H-pyrazol-4-yl)acetamide (1c)

(d) reacting 1(c) with a suitable reducing agent in the presence of an acid to yield 3-chloro-N-ethyl-1-(pyridin-3-yl)-1H-pyrazol-amine (1d)

(e) reacting 1(d) with a suitable activated carboxylic acid, carboxylic acid anhydride, or acid chloride of a carboxylic acid to yield thioether (1e)

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.

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 CH 2 (2,2-difluorocyclopropyl).

5. The process according to claim 1 further comprising oxidizing 1(e) with an oxidizing agent comprising hydrogen peroxide to yield

6. The process according to claim 1 , wherein R 1 is CH 2 CH 2 CF 3 and the suitable activated carboxylic acid, carboxylic acid anhydride, or acid chloride of a carboxylic acid is prepared from

which is prepared by the photochemical free-radical coupling of 3-mercaptopropionic acid and esters thereof with 3,3,3-trifluoropropene in the presence of 2,2-dimethoxy-2-phenylacetophenone initiator and long wavelength UV light in an inert organic solvent.