Reaktion #8600

Reaktionsgleichung

4-chloro-2-picoline

ethyl 4-fluorobenzoate

lithium bis(trimethylsilyl)amide

→

2-(4-chloro-2-pyridinyl)-1-(4-fluorophenyl)ethanone

Ausbeute 99.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeover 30 minutes
2. 2
   workup.ADDITIONUpon complete addition
3. 3
   Sonstigethe cold bath was removed
4. 4
   EinengenThe reaction mixture was concentrated under reduced pressure and methanol
5. 5
   workup.ADDITIONwas added to the reaction
6. 6
   Sonstigeresulting in the formation of a white precipitate
7. 7
   FiltrationThe precipitate was collected by filtration
8. 8
   Sonstigedried

Vorschrift

To a cold (0 ° C.) solution of 4-chloro-2-picoline (5.0 g,39 mmol) and ethyl 4-fluorobenzoate (6.6 g, 39 mmol) in tetrahydrofuran (100 mL) was added lithium bis(trimethylsilyl)amide (80 mL, 1.0 M in tetrahydrofuran, 80 mmol) dropwise via a pressure equalizing funnel over 30 minutes. Upon complete addition, the cold bath was removed and the resulting solution was stirred at room temperature for 15 hours. The reaction mixture was concentrated under reduced pressure and methanol was added to the reaction, resulting in the formation of a white precipitate. The precipitate was collected by filtration and dried to give 2-(4-chloro-2-pyridinyl)-1-(4-fluorophenyl)ethanone (9.6 g, 99%) as a white solid. 1H-NMR (DMSO-d6): δ 7.90 (m, 3H), 7.11 (t, 2H), 6.56 (s,1 H), 5.67 (s, 1 H), 4.14 (m, 2H); 19F-NMR (DMSO-d6): δ −115.67; MS m/z 250 (M+1).

Quelle