Reaktion #60012

Reaktionsgleichung

2,6-dibromopyridine

THF

n-BuLi

→

2-bromo-6-formylpyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigedegassed Et2O
2. 2
   Sonstige24.2 mL (300 mmol) of anhydrous degassed DMF
3. 3
   workup.ADDITIONwas added dropwise with rapid stirring
4. 4
   Temperaturto warm to room temperature (RT) overnight
5. 5
   TemperaturThe solution was cooled to −78° C.
6. 6
   workup.ADDITION100 mL of 1.0 M aq. HCl was added slowly
7. 7
   SonstigeThe organic phase was separated
8. 8
   Waschenthe aqueous phase was washed with 3×50 mL Et2O
9. 9
   Waschenwashed with 3×50 mL H2O and 3×50 mL brine
10. 10
    Trocknendried over Na2SO4
11. 11
    SonstigeThe volatiles were removed in vacuo
12. 12
    Sonstigeto provide an orange oil
13. 13
    SonstigeThe oil was triturated with hexanes

Vorschrift

To a solution of 23.7 g (100 mmol) of 2,6-dibromopyridine in 150 mL of anhydrous, degassed THF cooled to −78° C. was added dropwise under N2 a solution of 11.0 mL (110 mmol) of 10.0 M n-BuLi in 150 mL anhydrous, degassed Et2O. After 2 hours at −78° C., 24.2 mL (300 mmol) of anhydrous degassed DMF was added dropwise with rapid stirring. This solution was stirred at −78° C. for 2 hours, and was then allowed to warm to room temperature (RT) overnight. The solution was cooled to −78° C. and 100 mL of 1.0 M aq. HCl was added slowly. The organic phase was separated and the aqueous phase was washed with 3×50 mL Et2O. The organic washes were combined and washed with 3×50 mL H2O and 3×50 mL brine, then dried over Na2SO4. The volatiles were removed in vacuo to provide an orange oil. The oil was triturated with hexanes to give 2-bromo-6-formylpyridine as a pale orange solid that was washed with cold pentanes and dried under vacuum overnight.

Quelle