Hydrogen Peroxide → 1-Cyclohexyloxy-2,2,6,6-tetramethyl-piperidin-4-ol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 0.108 g (1.29 mmol) of sodium bicarbonate and 0.265 g (0.803 mmol) of sodium tungstate dihydrate in 2 ml of water is added to a mixture of 10.00 g (63.6 mmol) of 2,2,6,6-tetramethylpiperidin-4-ol and 9 ml of acetonitrile. A solution of 12.11 g (178 mmol) of 50% aqueous hydrogen peroxide is added to the reaction mixture dropwise over 3.75 hours as the reaction temperature is maintained at 35-38° C. The reaction mixture is heated at 35-38° C. for an additional 2 hours. The reaction mixture is diluted with acetonitrile and cyclohexane, and then saturated sodium chloride solution and solid sodium chloride are added. The aqueous layer is extracted twice with a mixture of cyclohexane and acetonitrile. The aqueous layer is discarded. To the combined organic layers are added cyclohexane and acetonitrile to bring the total amount of solvent to 65 ml and 95 ml, respectively. The reaction mixture is heated to near reflux, and a solution of 0.528 g (1.95 mmol) of ferric chloride hexahydrate and 0.628 g (6.53 mmol) of methanesulfonic acid in 5 ml of water is added over several minutes. A solution of 17.22 g (253 mmol) of 50% aqueous hydrogen peroxide is added to the reaction mixture dropwise over 4.75 hours as the reaction temperature is maintained at reflux (60° C.). A solution of 0.170 g of ferric chloride hexahydrate and 0.206 g of methanesulfonic acid in 2 ml of water is added to the reaction mixture 2.5 hours after the peroxide addition is begun. A solution of 0.178 g of ferric chloride hexahydrate and 0.205 g of methanesulfonic acid in 2 ml of water is added to the reaction mixture 4 hours after the peroxide addition is begun. The reaction mixture is heated at reflux for 30 minutes after the peroxide is added. Work up according to the procedure of Example 54 gives 11.07 g (68% yield) of the title compound. GC assay is 92%.

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