Lithium hydroxide, monohydrate → 3-(5-{(1R)-4-Cyclohexyl-1-[2-(hydroxyamino)-2-oxoethyl]butyl}1,2,4-oxadiazol-3-yl)propanoic acid

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Reaction Steps

A solution of ethyl 3-(5-{(1R)-4-cyclohexyl-1 -[2-(hydroxyamino)-2-oxoethyl]butyl}-1,2,4-oxadiazol-3- yl)propanoate (Example 54) (58 mg, 0.15 mmol) in 1,4-dioxan (2 ml) and water (1 ml) was treated with lithium hydroxide monohydrate (13 mg, 0.31 mmol) and stirred at room temperature for 2 hours. The reaction mixture was diluted with water and washed with diethylether (×2). The aqueous layer was acidified with hydrochloric acid (2M) (2 ml) and washed with ethyl acetate (×2). The combined organic layers were washed with brine, dried over anhydrous sodium sulphate, filtered and the solvent was removed under reduced pressure. The oil was purified by column chromatography on silica gel eluting with a gradient system of 100:0:0 (dichloromethane:methanol:acetic acid) gradually changing to 90:10:1 (dichloromethane:methanol:acetic acid) to afford the title compound as an orange gum (36 mg).

Provenance & Evidence