Water → 11-Bromoundecyl methacrylate

Methyl methacrylate (1.15 L, stabilised with 50 ppm of BHT), 11-bromoundecanol (200 g, 0.8 mole) and titanium tetraisopropoxide (11.4 g, 0.04 mole) are mixed together. A constant slow stream of dry air is bubbled through the reaction mixture during the reaction. The reaction mixture is heated under gentle reflux for 1 hour (internal temperature 90°). After this reflux period the methyl methacrylate/methanol azeotrope is removed under atmospheric distillation. During this time the internal temperature rises to 104° and the temperature at the still head rises from 65° to 101° (a total of 550 ml of distillate is collected). The reaction mixture is then cooled to 40° and quenched with water (1.5 ml, 2 equiv. based on titanium tetraisopropoxide). The resulting mixture is stirred for 3 hours then treated with celite (20 g). After stirring for a further 10 minutes the reaction mixture is filtered through a pad of celite. The filter pad is washed with methyl methacrylate (50 ml). The filtrate and wash are combined and distilled under vacuum (4-10 mmHg) at room temperature, then at 50°-60° to remove last traces of methyl methacrylate. During distillation a slow stream of dry air is bubbled through the residue in the distillation vessel. The product, 11-bromoundecyl methacrylate (233 g, 91% yield) is obtained as a pale yellow oil.

1. customA constant slow stream of dry air is bubbled through the reaction mixture during the reaction
2. temperatureThe reaction mixture is heated
3. temperatureunder gentle reflux for 1 hour (internal temperature 90°)
4. customAfter this reflux period the methyl methacrylate/methanol azeotrope is removed under atmospheric distillation
5. customrises to 104°
6. distillationthe temperature at the still head rises from 65° to 101° (a total of 550 ml of distillate is collected)
7. temperatureThe reaction mixture is then cooled to 40°
8. additionthen treated with celite (20 g)
9. stirringAfter stirring for a further 10 minutes the reaction mixture
10. filtrationis filtered through a pad of celite
11. washThe filter pad is washed with methyl methacrylate (50 ml)
12. washThe filtrate and wash
13. distillationdistilled under vacuum (4-10 mmHg) at room temperature
14. customat 50°-60° to remove last traces of methyl methacrylate
15. distillationDuring distillation a slow stream of dry air
16. customis bubbled through the residue in the distillation vessel

ORD record

ord-3fe7b9ee61e545cd8881a230adbb042b

Source dataset

uspto-grants-1995_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05441731