Sodium Hydroxide → 3-[4-(Trifluoromethoxy)phenyl]-2-{[4-(3,3,3-trifluoropropoxy)benzoyl]amino}propanoic acid

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Reaction Steps

DMF (three drops) and oxalyl chloride (3.50 mL, 40.0 mmol) were added to a methylene chloride (35 mL) solution of 4-(3,3,3-trifluoropropoxy)benzoic acid (4.68 g, 20.0 mmol) obtained in preparation process of Example 33 (33a), under ice-cooling with stirring. The mixture was stirred at room temperature for 3.5 hours, and then the solvent was evaporated. The obtained residue was dissolved in THF (20 mL). This solution and a 1 M sodium hydroxide aqueous solution (20 mL) were added dropwise simultaneously under ice-cooling with stirring to a solution mixture of a 1 M sodium hydroxide aqueous solution (40 mL) of 2-amino-3-[4-(trifluoromethoxy)phenyl]propanoic acid hydrochloride (5.71 g, 20.0 mmol) prepared in Reference Example 2, water (20 mL), and THF (15 mL). The resulting mixture was stirred under ice-cooling for 70 minutes, and then the solvents (mainly THF) were evaporated. Water was added to the residue, and the resulting mixture was changed to acidic by adding 2 M hydrochloric acid thereto. The precipitated crystalline solid was collected by filtration, washed with water and n-hexane, and dried under reduced pressure to give 8.75 g of the title compound (white powder, yield: 94%).

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