METHOD FOR PRODUCING (5S)-4-[5-(3,5-DICHLOROPHENYL)-5-(TRIFLUOROMETHYL)-4H-ISOXAZOL-3-YL]-2-METHYLBENZOIC ACID Russian patent published in 2022 - IPC C07D261/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a new method for the production of (5S)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-2-methylbenzoic acid according to formula 1(a). The method includes the steps of: i) reacting (5RS)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-2-methylbenzoic acid according to formula (1) with a compound formulas (2A), (2B) or (2C), where R is alkyl with 1 or 2 carbon atoms, X is Cl or Br, ii) separating the precipitate from step i) from the supernatant, iii) treating the precipitate from step ii) with an acidic aqueous solution and iv) separating (5S)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-2-methylbenzoic acid from the acidic aqueous solution of step iii) . The invention also contemplates a process for the preparation of (5S)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-N-[2-oxo-2-(2,2 ,2-trifluoroethylamino)ethyl]-2-methylbenzamide according to formula (3).

EFFECT: creation of a method for obtaining (5S)-4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-isoxazol-3-yl]-2-methylbenzoic acid with high enantiomeric excess, efficient high yield and simple system solvents.

14 cl, 3 tbl, 16 ex