反应详情

1. A 200 ml sulfonation flask is charged with 40.48 g (0.14 mol) of bis(2,2,6,6-tetramethyl-piperidin-4-yl)amine [EP-A-336 895, Ciba-Geigy] and 11.4 g (0.14 mol) of a 36% aqueous solution of formaldehyde. 25.8 g (0.56 mol) of formic acid are added dropwise at room temperature. The temperature in the flask rises to 70° C. with evolution of CO2. The reaction mixture is stirred until it has cooled to room temperature. The aqueous phase is then saturated with potassium carbonate and the reaction mixture is extracted three times with chloroform. The organic phases are combined, dried over potassium carbonate and concentrated on a vacuum rotary evaporator. Chromatography of the residue over silica gel using the solvent system hexane/dichloromethane 9:1+5% triethylamine gives 21 g (49%) of the methyl-bis(2,2,6,6-tetramethyl-piperidin-4-yl)amine, m.p. 51°-53° C., in the form of a white powder.

1. extractionsaturated with potassium carbonate and the reaction mixture is extracted three times with chloroform
2. dry with materialdried over potassium carbonate
3. concentrationconcentrated on a vacuum rotary evaporator