Diisopropylethylamine → 5-[5-(3,5-Dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid [(2,2,2-trifluoro-ethylcarbamoyl)-methyl]-amide

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Reaction Steps

DIPEA (0.246 ml) is added to a solution of (2,2,2-trifluoro-ethylcarbamoyl)-methyl-ammonium trifluoroacetate (0.170 g, Example 4, step B), PYBOP (0.270 g), and 5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid (0.2 g) in dichloromethane (3 ml) at 0° C. After 30 minutes at room temperature the reaction is quenched with water and extracted three times with dichloromethane. The combined organic phases are washed with a saturated aqueous solution of NaCl and a saturated aqueous solution of NaHCO3, dried over Na2SO4 and concentrated in vacuo. The crude product is purified on a semi-preparative reversed phase HPLC to yield 5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophene-2-carboxylic acid [(2,2,2-trifluoro-ethylcarbamoyl)-methyl]-amide (8.73 g) as a beige foam. MS (HPLC/MS): 562 (MH+). Retention time: 3.94 min.

Provenance & Evidence