Potassium Hydroxide → 2-(3-Chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionic acid

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Reaction Conditions

Reaction Steps

A solution of 2-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionic acid methyl ester and 2-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionic acid ethyl ester (prepared in Example 27, 937 mg) in ethanol (30 mL) at 25° C. was treated with a solution of potassium hydroxide (733 mg, 13.1 mmol) in water (7 mL). This solution was stirred at 25° C. for 3 h. At this time, the reaction mixture was concentrated in vacuo. The residue was acidified to pH=2 by treatment with a 1N aqueous hydrochloric acid solution. This solution was then extracted with methylene chloride (3×15 mL). The organics were dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 75/25 hexanes/ethyl acetate plus 1% acetic acid) afforded 2-(3-chloro-4-methanesulfonyl-phenyl)-3-cyclopentyl-propionic acid (787 mg, 82% over two steps) as a white solid: mp 123.9-126.2° C.; FAB-HRMS m/e calcd for C15H19ClO4S (M+H)+331.0771, found 331.0776.

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