反应详情

温度

75 °C

To a 300 ml three-necked flask fitted with a stirrer, nitrogen inlet, thermometer, condenser and Dean-Stark trap is added 34.45 g (0.2 mol) of 1-oxyl-2,2,6,6-tetramethylpiperidin-4-ol, 23.0 g (0.1 mol) of dimethyl sebacate and 110 ml of heptane. The reaction mixture is heated to reflux to dry the contents of the flask and 15 ml of slightly turbid distillate is removed from the Dean-Stark trap. The mixture is cooled to about 75° C. and 0.5 g of tetraisopropyl orthotitanate and 15 ml of heptane is added to the flask. The mixture is heated to reflux and heating at reflux temperature 100°-105° C. is continued for 24 hours with methanol being collected in the Dean-Stark trap. Water (5 ml) is added and heating is continued till all or most of the water is removed. The reaction mixture is allowed to cool slightly, is filtered and washed with heptane. Orange crystals form on standing and are collected by filtration, and washed with heptane. The orange crystalline product melts at 99°-101° C.

1. customTo a 300 ml three-necked flask fitted with a stirrer, nitrogen inlet
2. temperatureThe reaction mixture is heated
3. temperatureto reflux
4. customto dry the contents of the flask and 15 ml of slightly turbid distillate
5. customis removed from the Dean-Stark trap
6. addition0.5 g of tetraisopropyl orthotitanate and 15 ml of heptane is added to the flask
7. temperatureThe mixture is heated
8. temperatureto reflux
9. temperatureheating
10. temperatureat reflux temperature 100°-105° C.
11. customcollected in the Dean-Stark trap
12. additionWater (5 ml) is added
13. temperatureheating
14. customis removed
15. temperatureto cool slightly
16. filtrationis filtered
17. washwashed with heptane
18. customOrange crystals form on standing
19. filtrationare collected by filtration
20. washwashed with heptane