Pyridine → N-[(1R)-2-[(Methylsulfonyl)oxy]-1-phenylethyl]carbamic acid 1,1-dimethylethyl ester

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Reaction Steps

11 ml of pyridine and then 6.6 ml of methanesulfonyl chloride were added dropwise, at room temperature, to a solution containing 9.9 g of 2(R)-t-butoxycarbonylamino-2-phenylethanol [prepared as described in step (a) above] dissolved in 120 ml of methylene chloride. This mixture was stirred for 15 hours at room temperature, after which the solvent was removed by distillation. The residue was dissolved in ethyl acetate and water and the ethyl acetate layer was separated. This layer was washed with an aqueous solution of potassium hydrogen sulfate and an aqueous solution of sodium bicarbonate and then dried over anhydrous magnesium sulfate, after which the solvent was distilled off. The crystalline residue was collected by filtration and washed with a small amount of diisopropyl ether and cyclohexane to give 12.2 g of the title compound, melting at 108°-109° C.

Provenance & Evidence