Reaktion #1172673

Reaktionsgleichung

(2-methoxycarbonylbenzyl)triphenylphosphonium bromide

sodium hydride

hydrochloric acid

4-bromobenzaldehyde

→

methyl 2-(4-bromostyryl)benzoate

Ausbeute 55.1%

Lösungsmittel

methanol

water

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added to the suspension
2. 2
   workup.STIRRINGthe mixture was stirred at room temperature for 2 hours
3. 3
   workup.ADDITIONwere added
4. 4
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure
5. 5
   ExtraktionThe residue was extracted with 500 ml of ethyl acetate
6. 6
   WaschenAfter washing in sequence with saturated sodium bicarbonate aqueous solution
7. 7
   Trocknenwith saturated sodium chloride aqueous solution, the extract was dried over anhydrous magnesium sulfate
8. 8
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure The resulting residue
9. 9
   Sonstigewas recrystallized from methanol

Vorschrift

In 1.0 liter of tetrahydrofuran was suspended 60 g of (2-methoxycarbonylbenzyl)triphenylphosphonium bromide and, 3.2 g of sodium hydride was added to the suspension followed by stirring at room temperature for 3 hours. Then, 18 g of 4-bromobenzaldehyde was added and the mixture was stirred at room temperature for 2 hours. After completion of the reaction, 500 ml of water, 200 ml of methanol and 100 ml of 0.1 N hydrochloric acid aqueous solution were added thereto and the solvent was distilled off under reduced pressure. The residue was extracted with 500 ml of ethyl acetate. After washing in sequence with saturated sodium bicarbonate aqueous solution and then with saturated sodium chloride aqueous solution, the extract was dried over anhydrous magnesium sulfate and the solvent was distilled off under reduced pressure The resulting residue was recrystallized from methanol to give 17 g of methyl 2-(4-bromostyryl)benzoate as white needles.

Quelle