Barium hydroxide, octahydrate → (S,E)-2-(2,6-dichlorobenzamido)-5-[4-(4-methoxytetrahydropyran-4-yl)-phenyl]pent-4-enoic acid

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Reaction Conditions

Reaction Steps

In a mixed solvent of THF (250 ml) and water (125 ml), (S,E)-2-(2,6-dichlorobenzamido)-5-[4-(4-methoxytetrahydropyran-4-yl)-phenyl]pent-4-enoic acid methyl ester (9.80 g) was dissolved, and the resulting mixture was cooled to 0° C. Barium hydroxide octahydrate (3.14 g) was added thereto and the resulting mixture was stirred at 0° C. for 8 hours. The reaction solution was concentrated to remove THF, and water (150 ml) was added thereto, followed by washing the resulting mixture with ether. Aqueous layer was acidified by adding 1N hydrochloric acid in small portions thereto and extracted 3 times with ethyl acetate. Organic layers were washed with saturated brine and dried over anhydrous sodium sulfate. After removing anhydrous sodium sulfate by filtration, the filtrate was concentrated. The residue was purified by column chromatography (silica gel, eluent: chloroform/methanol=10/1). The obtained crude product was further purified by column chromatography (silica gel, eluent: cyclohexane/ethyl acetate=1/1→ethyl acetate) to obtain (S,E)-2-(2,6-dichlorobenzamido)-5-[4-(4-methoxytetrahydropyran-4-yl)-phenyl]pent-4-enoic acid (6.15 g).

Provenance & Evidence