Реакция #160689

Уравнение реакции

1,5-dibromopentane

vanillin

potassium carbonate

→

product 44

Выход 80.0%

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

Выход 80.0%

Растворители

acetone

Условия реакции

Обработка

1. 1
   ТемператураThe reaction mixture was heated
2. 2
   Температураat reflux for 2.5 hours
3. 3
   Другоеthe reaction
4. 4
   ФильтрацияThe suspension was subjected to vacuum filtration
5. 5
   Другоеthe resulting acetone solution was evaporated to dryness under reduced pressure
6. 6
   Промывкаwashed with 10% ethyl acetate in hexane (2 L)
7. 7
   Промывкаto elute
8. 8
   Другоеthe product, removal of excess solvent
9. 9
   Другоеby rotary evaporation under reduced pressure

Методика

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).

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