Hydrochloric Acid → 1-Cyclohexyloxy-2,2,6,6-tetramethyl-piperidin-4-ol

Beteiligte Stoffe

Reaktionsschritte

Nanosized activated iron powder in mineral oil (0.042 g) is rinsed successively with two 2 ml portions of cyclohexane. Most of the solvent is removed with a pipette. The iron is added to a mixture of 5.00 g (29.0 mmol) of 1-oxyl-2,2,6,6-tetramethylpiperidin-4-ol, 44 ml of acetonitrile, and 32 ml of cyclohexane that has been heated to 40 degrees. To this mixture is carefully added over several minutes a solution of 0.548 g of concentrated hydrochloric acid in 3 ml of water. The reaction temperature is brought to reflux and a solution of 7.81 g (115 mmol) of 50% aqueous hydrogen peroxide is added dropwise over a period of 2.25 hours. After about one-half of the peroxide solution is added, a second portion of nanosized activated iron powder in mineral oil (0.039 g), rinsed twice with cyclohexane, and a solution of 0.166 g of concentrated hydrochloric acid in 1 ml of water are added to the reaction mixture. The reaction mixture is heated at 60-62 degrees for 1.5 hours after the peroxide has been added. After work up and purification according to the procedure of Example 54, the yield of the title compound is 5.53 g (75% yield), GC assay 96%.

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