Réaction #8600

Équation de réaction

4-chloro-2-picoline

ethyl 4-fluorobenzoate

lithium bis(trimethylsilyl)amide

→

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

Rendement 99.0%

Solvants

tetrahydrofuran

Conditions de réaction

Traitement

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

Mode opératoire

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).

Source