Processes for the preparation of pesticidal compounds
AssigneeDow AgroSciences LLC
InventorsQiang Yang, Beth Lorsbach, Ronald Ross, Jr., Kaitlyn Gray, Yu Zhang, Gary Roth
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Abstract
The present application provides processes for making pesticidal compounds and compounds useful both as pesticides and in the making of pesticidal compounds.
Claims19
A process for the preparation of 3-chloro-N-ethyl-1H-pyrazol-4-amine (7a) useful in the preparation of pesticidal thioethers (7b), (1e) and pesticidal sulfoxides (1f),
- which comprises reducing N-(3-chloro-1H-pyrazol-4-yl)acetamide (1b)
- with a suitable reducing agent in the presence of an acid.
A process for the preparation of thioether (7b) useful as pesticides and in the preparation of pesticidal sulfoxides (1f),
- wherein R1 is selected from the group consisting of C1-C4 haloalkyl and C1-C4 alkyl-C3-C6 halocycloalkyl, said process which comprises acylating 3-chloro-N-ethyl-1H-pyrazol-4-amine (7a)
- with an acyl chloride of the formula C1C(O)CH2CH2SR1 in the presence of a base.
A compound 3-chloro-N-ethyl-1H-pyrazol-4-amine (7a)
A compound N-(3-chloro-1H-pyrazol-4-yl)-N-ethyl-3-((3,3,3-trifluoropropyl)thio)propanamide (Compound 4.7):
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 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) mono-acylation of 3-chloro-1H-pyrazol-4-amine hydrochloride (1a) to yield
- with acetic anhydride in the presence of a base;
- (c) reducing (1b) with a suitable reducing agent in the presence of an acid to yield 3-chloro-N-ethyl-1H-pyrazol-4-amine (7a)
- (d) acylating (7a) wherein R1 is selected from the group consisting of C1-C4 haloalkyl and C1-C4 alkyl-C3-C6 halocycloalkyl, to yield thioether (7b)
- (e) heteroaryling (7b) with a halopyridine in the presence of a copper salt, an amine, and a base to yield thioether (1e)
Dependencies are inferred from the claim text.