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US 9,126,974 B2Granted
Processes for the preparation of pesticidal compounds
AssigneeDow AgroSciences LLC
InventorsQiang Yang, Beth Lorsbach, Ronald Ross, Jr., Kaitlyn Gray, Yu Zhang, Gary Roth
Life of this patent
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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.
Claims23
A process for the preparation of thioether (7b) useful as a pesticide,
- wherein R1 is selected from the group consisting of C1-C4 haloalkyl and C1-C4 alkyl-C3-C6 halocycloalkyl, the process comprising acylating 3-chloro-N-ethyl-1H-pyrazol-4-amine (7a)
- with an acyl chloride of the formula ClC(O)CH2CH2SR1 in the presence of sodium bicarbonate in a mixture of tetrahydrofuran and water.
A process comprising:
- (a) halogenating and reducing 4-nitropyrazole
- with concentrated hydrochloric acid at a temperature between about 0° C. and about 40° C. with between about 1 and about 4 equivalents of triethylsilane and about 5 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 at a temperature between about 0° C. and about 40° C.;
- (c) reducing (1b) with a suitable reducing agent in the presence of a Lewis acid to yield 3-chloro-N-ethyl-1H-pyrazol-4-amine (7a)
- (d) contacting (7a) with an acid chloride of the formula Cl—C(O)—C1C4-alkyl-S—R1, wherein R1 is selected from the group consisting of C1-C4 haloalkyl and C1-C4 alkyl-C3-C6 halocycloalkyl, in the presence of a base to yield thioether (7b)
- (e) contacting (7b) with a halopyridine in the presence of a copper salt, an amine and a base, at a temperature of between about 50° C. and about 110° C., to yield thioether (1e)
4 more elements
Dependencies are inferred from the claim text.