Sodium Hydroxide → (Z)-2-[[2-chloro-4-[3-(3-hydroxyphenyl)-1-oxopropan-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 (0.6 mL, 0.6 mmol) was added to a solution of (Z)-2-[[2-chloro-4-[3-(3-hydroxyphenyl)-1-oxopropan-1-yl]benzoyl]amino]-3-(2,4-dimethylthiazol-5-yl)propenoic acid methyl ester (Example 227; 95 mg, 0.19 mmol) in methanol/tetrahydrofuran (1:1; 2.4 mL). The solution was stirred at room temperature for 6 h and the solvent was evaporated. Water (5 mL) was added and the mixture was extracted with diethyl ether. The organic extract was discarded and the aqueous layer was acidified with 1N hydrochloric acid solution (0.6 mL) and stirred for 30 min at room temperature. The resulting precipitate was filtered off, washed with water, dried and crystallized from tetrahydrofuran/methanol/water to furnish (Z)-2-[[2-chloro-4-[3-(3-hydroxyphenyl)-1-oxopropan-1-yl]benzoyl]amino]-3-(2,4-dimethylthiazol-5-yl)propenoic acid (65 mg, 71% yield) as a colorless solid.

Provenance & Evidence