Sodium Hydroxide → Rac.-(z)-2-[[2-chloro-4-[1-hydroxy-3-(3-hydroxyphenyl)propan-1-yl]benzoyl]amino]-3-(2,4-dimethylthiazol-5-yl)propenoic acid

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Reaction Steps

An aqueous 1N solution of sodium hydroxide (0.5 mL, 0.5 mmol) was added to a solution of rac.-(Z)-2-[[2-chloro-4-[1-hydroxy-3-(3-hydroxyphenyl)propan-1-yl]benzoyl]amino]-3-(2,4-dimethylthiazol-5-yl)propenoic acid methyl ester (Example 229; 70 mg, 0.14 mmol) in methanol/tetrahydrofuran (1:1; 2 mL). After the solution was stirred at room temperature for 5 h and the solvents were removed under reduced pressure. Water (5 mL) was added and the mixture was filtered through Celite®. The filter pad was washed with water (2 mL) and the combined filtrates were acidified with 1N hydrochloric acid solution (0.5 mL). The mixture was stirred for 1 h, then the solids were filtered off, washed with water, dried and crystallized from tetrahydrofuran/methanol/water to give rac.-(Z)-2-[[2-chloro-4-[1-hydroxy-3-(3-hydroxyphenyl)propan-1-yl]benzoyl]amino]-3-(2,4-dimethylthiazol-5-yl)propenoic acid (39.3 mg, 58% yield) as a colorless solid.

Provenance & Evidence