4-Toluenesulfonyl chloride → tert-Butyl (3R)-6-cyclohexyl-3-[3-({[(4-methylphenyl)sulfonyl]oxy}methyl)1,2,4-oxadiazol-5-yl]hexanoate

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Reaction Conditions

Reaction Steps

A suspension of sodium hydride 60% suspension in mineral oil (1.52 g, 38.00 mmol) in anhydrous tetrahydrofuran (30 ml) was cooled to 0° C. and treated with a solution of tert-butyl (3R)-6-cyclohexyl-3-[3-(hydroxymethyl)-1,2,4-oxadiazol-5-yl]hexanoate (Preparation 176) (13.40 g, 38.00 mmol) in anhydrous tetrahydrofuran (120 ml) and stirred under a nitrogen atmosphere for 30 minutes. p-Toluene sulphonyl chloride (7.25 g, 38.00 mmol) was added portionwise and the mixture was allowed to warm to room temperature over 18 hours. The solvent was removed under reduced pressure The residue was dissolved in ethyl acetate and washed with water, saturated sodium hydrogen carbonate solution and brine, dried over anhydrous sodium sulphate, filtered and the solvent removed under reduced pressure. The oil was purified by column chromatography on silica gel eluting with dichloromethane to afford the title compound (10.75 g).

Provenance & Evidence