p-Toluenesulfonic acid → 2-(4-Bromo-2,6-dimethylphenyl)-1,3-dioxane

Temperatur

140 °C

A mixture of 4-bromo-2,6-dimethylbenzaldehyde (2.51 g, 12 mmol), 4-methyl-benzenesulfonic acid (0.20 g, 1.2 mmol), and propane-1,3-diol (1.2 mL, 16 mmol) in toluene (200 mL) was heated under nitrogen at 140° C. for 16 h, using a Dean-Stark trap to remove water. The reaction solution was then cooled to 25° C., diluted with EtOAc (200 mL), and sequentially washed with saturated aqueous sodium bicarbonate solution (100 mL) and brine (100 mL). The organic layer was separated, dried over MgSO4, filtered, and concentrated in vacuo to provide a yellow-brown oil. Hexane (200 mL) was added to the oil, and the resulting mixture was stirred vigorously for 10 min, resulting in the precipitation of a solid. This solid was collected by vacuum filtration, washed with hexanes (100 mL), and dried in vacuo to provide 2-(4-bromo-2,6-dimethylphenyl)-1,3-dioxane as a tan solid.

1. customto remove water
2. temperatureThe reaction solution was then cooled to 25° C.
3. additiondiluted with EtOAc (200 mL)
4. washsequentially washed with saturated aqueous sodium bicarbonate solution (100 mL) and brine (100 mL)
5. customThe organic layer was separated
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customto provide a yellow-brown oil
10. customresulting in the precipitation of a solid
11. filtrationThis solid was collected by vacuum filtration
12. washwashed with hexanes (100 mL)
13. customdried in vacuo

ORD-Eintrag

ord-4637d778b57747399612fe8a89d9acbd

Quelldatensatz

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07842685B2