Dimethyl Sulfoxide → 1-Methoxy-2,2,6,6-tetramethyl-piperidin-4-ol

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Reaction Steps

A solution of 17.8 g (64.0 mmol) of ferrous sulfate heptahydrate in 100 ml of water is added dropwise, under nitrogen, over an 8-minute interval to a mixture of 10.0 g (58.1 mmol) of 4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine, 14.5 g (128 mmol) of 30% aqueous hydrogen peroxide, and 200 ml of dimethyl sulfoxide. As the ferrous sulfate solution is added, an ice-water bath is used to keep the reaction temperature at 20° C.-40° C. After the addition is complete, the mixture is stirred for 15 minutes at ambient temperature and then extracted with methylene chloride (200 ml, then 100 ml). Purification of the crude product by flash chromatography on silica gel (10:1 heptane/ethyl acetate, then 4:1 heptane/ethyl acetate) affords 5.7 g (52% yield) of the title compound.

Provenance & Evidence