Lithium hydroxide, monohydrate → ({3-[5-(3,5-Dichloro-4-fluoro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-5,6-dihydro-4H-cyclopenta[c]thiophene-1-carbonyl}-amino)-acetic acid

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Reaction Steps

Stir a mixture of ({3-[5-(3,5-Dichloro-4-fluoro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-5,6-dihydro-4H-cyclopenta[c]thiophene-1-carbonyl}-amino)-acetic acid methyl ester (11 g, 18.6 mmol) and LiOH—H2O (1.56 g, 37.2 mmol) in THF (100 mL) and water (50 mL) at room temperature for overnight. After being checked with TLC, the solvent is removed under vacuum, dilute the residue with water (50 mL). Acidify the aqueous mixture with 2M HCl to pH=3, and extract the resultant mixture with EtOAc (100 mL×3), the combined organic layer is washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum, the residue is purified by silica gel chromatograph (PE:EtOAc 1:1) to afford ({3-[5-(3,5-Dichloro-4-fluoro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-5,6-dihydro-4H-cyclopenta[c]thiophene-1-carbonyl}-amino)-acetic acid as a white solid (10.2 g, 90.7% for two steps). MS (m/z): 525 (M+1).

Provenance & Evidence