4-Chlorophenol → (S)-4-[2-(4-chloro-phenoxy)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

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Reaction Steps

To a stirred solution of tert-butyl(S)-4-(2-hydroxyethyl)-2,2-dimethyloxazolidine-3-carboxylate (411 mg; CAS 147959-18-0) in THF (6 ml) were added 4-chlorophenol (283 mg), triphenylphosphine (630 mg) and diethyl azodicarboxylate (40% in toluene, 0.92 ml). The resulting yellow solution was placed in a microwave oven at 100° C. for 20 min. Sodium hydroxide solution (1M) and ethyl acetate were added, after separation the organic layer was washed a second time with 1M sodium hydroxide solution, dried over magnesium sulphate and concentrated in vacuo. The crude product was purified by column chromatography (SiO2; gradient: heptane/EtOAc 100:0→90:10) to give (S)-4-[2-(4-chloro-phenoxy)-ethyl]-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (540 mg, 76%) as a light yellow oil. MS (ISP): 356.1 ([M+H]+)).

Provenance & Evidence