反应详情

After the addition of 1 g of tetrabutyl-orthotitanate, 47 g of dimethyl diethylmalonate and 98.6 g of 1-allyl-2,2,6,6-tetramethyl-4-hydroxypiperidine in 100 ml of xylene are heated under a gentle stream of nitrogen to about 140°. The methanol forming during the reaction is continuously distilled off, and after about 6 hours the reaction is virtually completed. The reaction mixture is diluted with 200 ml of toluene, extracted three times with 100 ml of water each time, dried over sodium sulphate and concentrated by evaporation. Crystallisation of the residue from hexane yields bis-(1-allyl-2,2,6,6-tetramethyl-4-piperidinyl) diethylmalonate (compound 18), m.p. 135°-136°.

1. temperatureare heated under a gentle stream of nitrogen to about 140°
2. distillationThe methanol forming during the reaction is continuously distilled off
3. additionThe reaction mixture is diluted with 200 ml of toluene
4. extractionextracted three times with 100 ml of water each time
5. dry with materialdried over sodium sulphate
6. concentrationconcentrated by evaporation
7. customCrystallisation of the residue from hexane