Réaction #160689

Équation de réaction

1,5-dibromopentane

vanillin

potassium carbonate

→

product 44

Rendement 80.0%

4-(6-bromo-hexanoyl)-3-methoxy-benzaldehyde

Rendement 80.0%

Solvants

acetone

Conditions de réaction

Traitement

1. 1
   TempératureThe reaction mixture was heated
2. 2
   Températureat reflux for 2.5 hours
3. 3
   Autrethe reaction
4. 4
   FiltrationThe suspension was subjected to vacuum filtration
5. 5
   Autrethe resulting acetone solution was evaporated to dryness under reduced pressure
6. 6
   Lavagewashed with 10% ethyl acetate in hexane (2 L)
7. 7
   Lavageto elute
8. 8
   Autrethe product, removal of excess solvent
9. 9
   Autreby rotary evaporation under reduced pressure

Mode opératoire

An excess of 1,5-dibromopentane (100 g, 3 equivalents) was added to a suspension of vanillin (43) (22 g) and potassium carbonate (30 g) in acetone (700 mL). The reaction mixture was heated at reflux for 2.5 hours and then allowed to stir at room temperature overnight, at which time TLC and LC/MS showed the reaction to be complete. The suspension was subjected to vacuum filtration and the resulting acetone solution was evaporated to dryness under reduced pressure. The residue was applied to a pad of silica gel and washed with 10% ethyl acetate in hexane (2 L) followed by 25% ethyl acetate in hexane to elute the product, removal of excess solvent by rotary evaporation under reduced pressure afforded the product 44 as an oil which crystallised on standing in freezer (35 g, 80% yield).

Source