Acetic Acid → N-cyclohexyloxy-4-oxo-2,2,6,6-tetramethylpiperidine

Participants

Reaction Conditions

Reaction Steps

1-Oxyl-2,2,6,6-tetramethylpiperidin-4-one (10.97 g, 64.4 mmol) is divided into 2 portions. A solution of 0.216 g (1.09 mmol) of ferrous chloride tetrahydrate and 0.185 9 (3.08 mmol) of glacial acetic acid in 3 ml of water is added to a mixture of 2 g of 1-oxyl-2,2,6,6-tetramethylpiperidin-4-one, 20 ml of acetonitrile, and 13 ml of cyclohexane that is heated to near reflux. A solution of 17.21 g (253 mmol) of 50% aqueous hydrogen peroxide is added to the reaction mixture dropwise over 4.75 hours as the reaction temperature is brought to and maintained at 60-62° C. As the peroxide is being added, a solution of the remaining portion of 1-oxyl-2,2,6,6-tetramethylpiperidin-4-one in 20 ml of acetonitrile is added to the reaction mixture dropwise over 3.5 hours. During the addition of the 1-oxyl compound, cyclohexane (47 ml) and acetonitrile (50 ml) are added to the reaction mixture in several portions. A total of 0.326 g of ferrous chloride tetrahydrate, 0.284 g of glacial acid, and 4 ml of water is added to the reaction mixture in 3 portions during the peroxide addition. Work up according to the procedure of Example 44 affords 10.31 g (63% yield) of the title compound. GC assay is 99%.

Provenance & Evidence