Réaction #1994296

Équation de réaction

4-chloro-2-fluorobenzaldehyde

sodium hydroxide

acetone

dichloromethane

→

4-(4-chloro-2-fluorophenyl)-3-buten-2-one

Rendement 76.0%

(E)-4-(4-chloro-2-fluorophenyl)-but-3-en-2-one

Rendement 76.0%

Solvants

water

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONwas added
2. 2
   AutreThe aqueous layer was separated
3. 3
   Extractionextracted with CH2Cl2 (100 mL)
4. 4
   Lavagethe combined organic extracts were washed with brine
5. 5
   Séchagedried over magnesium sulfate (MgSO4)
6. 6
   AutreSolvent removal
7. 7
   workup.DISTILLATIONfollowed by Kugelrohr distillation

Mode opératoire

To a mechanically stirred solution of 4-chloro-2-fluorobenzaldehyde (23.8 grams (g), 0.15 mole (mol)) in acetone (100 milliliters (mL)) at room temperature was added over 20 minutes (min) a solution of sodium hydroxide (NaOH, 6.6 g, 0.165 mol) in water (H2O, 400 mL). After stirring the reaction mixture overnight, dichloromethane (CH2Cl2, 100 mL) was added. The aqueous layer was separated and extracted with CH2Cl2 (100 mL), and the combined organic extracts were washed with brine and dried over magnesium sulfate (MgSO4). Solvent removal followed by Kugelrohr distillation gave 4-(4-chloro-2-fluorophenyl)-3-buten-2-one (1; 22.5 g, 76%) as a colorless liquid, which solidified upon standing: by 70-80° C., 0.1 mmHg (13.33 pascals (Pa)); 1H NMR (400 MHz, CDCl3) δ 7.59 (d, J=16.5 Hz, 1H), 7.50 (t, J=8.1 Hz, 1H), 7.22-7.12 (m, 2H), 6.76 (d, J=16.5 Hz, 1H), 2.39 (s, 3H); HRMS-ESI (m/z): calcd for C10H8ClFO, 198.024. found 198.025.

Source