Hydrogen Peroxide → 4-Piperidinol, 1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethyl-

Participants

Reaction Conditions

Reaction Steps

A solution of 50.7 g (0.75 mol) of 50% aqueous hydrogen peroxide mixed with 25 mL of tert-butyl alcohol is added over two hours to a mixture of 25.8 g (0.15 mol) of 4-hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine, 8.95 g (0.045 mol) of ferrous chloride tetrahydrate and 110 mL of tert-butyl alcohol at 50° C. The reaction mixture is then maintained at 50° C. for six hours and monitored by gas chromatography. Another 17.7 g (0.26 mol) of 50% hydrogen peroxide is added and the reaction mixture is heated at 50° C. for two more hours to bring about complete reaction of the starting nitroxyl compound. The reaction mixture is filtered to remove solids, and the filtrate is diluted with water. The tert-butyl alcohol-water solution is extracted three times with methylene chloride and the aqueous layer is thoroughly extracted with ethyl acetate to afford 7.4 g of the title compound. The combined organic layers are washed once with saturated sodium chloride, dried over anhydrous magnesium sulfate and concentrated to give 21.7 g of an orange oil. The orange oil is purified by flash chromatography on silica gel with 3:2 heptane:ethyl acetate to afford another 12.4 g of the title compound and 4.2 g of a compound which has the same retention time by gas chromatography as an authenic sample of 1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethylpiperidin-4-one.

Provenance & Evidence