m-Chloroperbenzoic acid → Di-tert-butyl (5-{2-fluoro-4-[(5R)-2-oxo-5-(1H-1,2,3-triazol-1-ylmethyl)-1,3-oxazolidin-3-yl]phenyl}isoxazol-3-yl)methyl phosphate

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Reaction Steps

(5R)-3-{3-Fluoro-4-[3-(hydroxymethyl)isoxazol-5-yl]phenyl}-5-(1H-1,2,3-triazol-1-ylmethyl)-1,3-oxazolidin-2-one (Example 3, 0.1 g, 0.3 mmol) was suspended in dichloromethane (3 ml), and di-tert-butyl-N,N-diethylphosphoramidite (93 μl, 0.3 mmol) and 1H-tetrazole (35 mg, 0.5 mmol) were added sequentially. The mixture was stirred under nitrogen at room temperature for 1.5 hours. Solution was cooled to 0° C. and m-chloroperbenzoic acid (≈70%, 0.1 g, 0.4 mmol) was added. The reaction was stirred at 0° C. under nitrogen for 2 hours. After warming to room temperature, saturated sodium bisulfite (3 ml) was added and the mixture stirred for 5 minutes followed by dilution with dichloromethane (10 ml). After the layers were separated, the aqueous phase was extracted with dichloromethane (3×10 ml); the combined organics were washed with saturated sodium bicarbonate, and brine, and dried over sodium sulfate. The crude material was purified by chromatography (using a Jones Flashmaster) using 0–5% methanol in dichloromethane as eluent. Relevant fractions were combined giving 91 mg of the desired product as a white solid.

Provenance & Evidence