US 12,466,787 B2
Process for synthesis of high purity 1-[3-(trifluoromethyl)phenyl]ethanone oxime
Ravi Goenka, Mumbai (IN); and Ajay A Audi, Mumbai (IN)
Assigned to LAXMI ORGANIC INDUSTRIES LTD, Mumbai (IN)
Appl. No. 17/904,964
Filed by LAXMI ORGANIC INDUSTRIES LTD, Mumbai (IN)
PCT Filed Apr. 23, 2020, PCT No. PCT/IN2020/050378
§ 371(c)(1), (2) Date Aug. 25, 2022,
PCT Pub. No. WO2021/171301, PCT Pub. Date Sep. 2, 2021.
Claims priority of application No. 202021007935 (IN), filed on Feb. 25, 2020.
Prior Publication US 2023/0167051 A1, Jun. 1, 2023
Int. Cl. C07C 249/08 (2006.01); C07C 17/35 (2006.01); C07C 45/68 (2006.01)
CPC C07C 249/08 (2013.01) [C07C 17/35 (2013.01); C07C 45/68 (2013.01)] 9 Claims
 
1. A process for preparation of 3-Trifluoromethyl acetophenone oxime of formula I, comprising:
a) reacting an isomeric mixture of a halo benzotrifluoride of formula Ia with Mg metal in an organic solvent in presence of a catalyst to obtain a Grignard complex of formula Ib, wherein said formulae Ia and Ib are respectively as follows, in which X is halogen:

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b) reacting the Grignard complex of said formula Ib with a ketene of formula Ic in a hydrocarbon solvent in the presence of a transition metal ligand-acid complex to obtain an isomeric mixture of trifluoromethyl acetophenone of formula Id, wherein said formulae Ic and Id are respectively as follows:

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and
c) reacting the isomeric mixture of trifluoromethyl acetophenone of said formula Id with a hydroxylamine salt to obtain the 3-Trifluoromethyl acetophenone oxime of formula I, wherein said formula I is as follows:

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