Reaktion #48540

Reaktionsgleichung

iso-propylmagnesium chloride

3,5-dibromofluorobenzene

3,5-dibromo-fluoro-benzene

THF

THF

THF

THF

→

28

Ausbeute 100.5%

3-bromo-5-fluoro-benzaldehyde

Ausbeute 100.5%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwhile maintaining the temperature at ca. 0 C
2. 2
   WaschenAfter rinsing with THF (3×20 mL) the mixture
3. 3
   workup.ALIQUOTThe reaction was sampled by HPLC
4. 4
   Temperaturcooled to ca. 0° C
5. 5
   workup.ADDITIONDMF was added over 0.5 h
6. 6
   Temperaturwhile maintaining the temperature at ca. 0° C
7. 7
   workup.WAITThe mixture was aged 1.5 h at ca. 0° C.
8. 8
   Temperaturwarmed slowly to ca. 20° C. overnight
9. 9
   workup.ALIQUOTAfter sampling by HPLC
10. 10
    workup.ADDITIONthe mixture was diluted with heptane (200 mL)
11. 11
    workup.ADDITIONwith a mixture of con HCl (120 mL)
12. 12
    workup.ADDITIONdiluted to 360 mL with water
13. 13
    workup.ADDITIONCon HCl (50 mL) was added
14. 14
    SonstigeThe organic phase was separated
15. 15
    Waschenwashed with water (400 mL)
16. 16
    Sonstigeevaporated to dryness

Vorschrift

step 1—To a solution of iso-propylmagnesium chloride in THF (500 mL of a 2M solution in THF, 1.0 mol) and THF (200 mL) was added a solution of 3,5-dibromofluorobenzene (25; 200 g, 0.79 mol) in THF (100 mL) while maintaining the temperature at ca. 0 C. After rinsing with THF (3×20 mL) the mixture was aged for 2 h at ca. 0° C. and then warmed to ca. 20° C. and aged for 0.5 h. The reaction was sampled by HPLC and then cooled to ca. 0° C. DMF was added over 0.5 h while maintaining the temperature at ca. 0° C. The mixture was aged 1.5 h at ca. 0° C. and then warmed slowly to ca. 20° C. overnight. After sampling by HPLC, the mixture was diluted with heptane (200 mL) and then with a mixture of con HCl (120 mL) diluted to 360 mL with water. Con HCl (50 mL) was added to adjust the pH to <7. The organic phase was separated, washed with water (400 mL) and evaporated to dryness to afford 160.8 g (100.5%) of 28 as a yellow oil which solidified on standing.

Quelle