Hydrochloric Acid → 3,5-Dibromo-1-trimethylsilylbenzene

Temperatur

-55 °C

42.4 g of Tribromobenzene (134.6 mmol) was dissolved in 600 mL Et2O. The solution was chilled to −55° C., at which temperature starting material precipitated. 54 mL of n-BuLi (2.5 M in hexanes, 135 mmol) were added within 20 minutes. After stirring for 35 minutes at −52° C., 20 ml TMSCl (158 mmol) and 20 mL Et2O were added within 7 minutes. The suspension turned into a solution at −42° C., and a fine precipitate appeared at −30° C. The suspension was stirred overnight at room temperature. 100 mL 2M HCl were used to hydrolyze the mixture. After stirring for 30 minutes, the Et2O-phase was dried with MgSO4, filtered, and solvent evaporated until compound crystallized out of solution. The flask was stored overnight at +4° C. The crystalline compound was filtered, washed with a small amount cold pentane, and dried under vacuo. A second fraction of crystalline compound was obtained from the filtrate. Yield: 31.9 g (103.5 mmol, 77%). 1H-NMR (CHCl3=7.24 ppm): δ 7.62 (t, 1H), 7.49 (d, 2H), 0.25 (s, 3×3H).

1. customprecipitated
2. customturned into a solution at −42° C.
3. customappeared at −30° C
4. stirringThe suspension was stirred overnight at room temperature
5. stirringAfter stirring for 30 minutes
6. dry with materialthe Et2O-phase was dried with MgSO4
7. filtrationfiltered
8. customsolvent evaporated until compound
9. customcrystallized out of solution
10. waitThe flask was stored overnight at +4° C
11. filtrationThe crystalline compound was filtered
12. washwashed with a small amount cold pentane
13. customdried under vacuo
14. customA second fraction of crystalline compound was obtained from the filtrate

ORD-Eintrag

ord-e556357acb064e8babf5fa3f864b2fab

Quelldatensatz

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06376411B1