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US 11,530,187 B2Granted
Method for producing (5S)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-2-methyl-benzoic acid
AssigneeIntervet Inc.
InventorHarald Schmitt
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Abstract
The present invention relates to a novel method for preparing (5S)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-2-methyl-benzoic acid, which can preferably be used in the synthesis of (5S)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-N-[2-oxo-2-(2,2,2-trifluoroethylamino)ethyl]-2-methyl-benzamide.
Claims16
A Method for preparing (S) 4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4Hisoxazol-3yl)]-2-methyl-benzoic acid according to Formula (1a)
- from (RS) 4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl)]-2-methyl-benzoic acid according to Formula (1)
- comprising the steps of:
- (i) reacting (RS) 4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl)]-2-methyl-benzoic acid with a compound of Formula (2A), (2B) or (2C)
- wherein R is an alkyl with 1 or 2 carbon atoms,
- wherein X is Cl or Br,
- in an organic solvent having a polarity ET(30) between 130 and 175 kJ/mol to form a precipitate and a supernatant solution
- (ii) separating the precipitate from step (i) from the supernatant solution
- (iii) treating the precipitate from step (ii) with acidic aqueous solution, and
- (iv) separating (S)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl)]-2-methyl-benzoic acid from the acidic aqueous solution of step (iii), under the proviso that, when R is methyl, the solvent in step (i) is not ethyl acetate.
6 more elements
Dependencies are inferred from the claim text.