Benzathine → (RS)-4-{4-[3-(4-chloro-phenyl)-ureido]-phenyl}-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A stirred suspension of (RS)-4-(4-iodo-phenyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (1.60 g), 4-chlorophenylurea (0.81 g), potassium fluoride (2.88 g, 40 wt % on alumina), N,N′-dibenzylethylenediamine (0.14 ml) and copper(I) iodide (0.11 g) in THF (16 ml) in a sealed tube was heated at 90° C. for 30 minutes under microwave irradiation. The mixture was then cooled to room temperature and filtered through celite. The filtrate was concentrated in vacuo and the residue was purified by column chromatography (SiO2; gradient: heptane/EtOAc) to give (RS)-4-{4-[3-(4-chloro-phenyl)-ureido]-phenyl}-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (0.24 g, 14%) as a light yellow solid. MS (ISP): 392.1 ([{37Cl}M+H—C4H8]+), 390.1 ([{35Cl}M+H—C4H8]+).

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