Reaktion #5124

Reaktionsgleichung

hydrochloric acid

potassium carbonate

benzyl bromide

3,4-dihydroxylphenyl acetic acid ethyl ester

→

3-benzyloxy-4-hydroxyphenylacetic acid ethyl ester

Ausbeute 45.0%

Lösungsmittel

water

acetone

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was heated
2. 2
   Temperaturto reflux until the starting materials
3. 3
   workup.DISTILLATIONand then the solvent was distilled off under reduced pressure
4. 4
   SonstigeTo the residues thus obtained
5. 5
   Extraktionextracted with dichloromethane
6. 6
   TrocknenThe organic layer was dried over magnesium sulfate
7. 7
   Sonstigeevaporated under reduced pressure
8. 8
   Sonstigeto obtain residues, which
9. 9
   Sonstigewere purified by chromatography

Vorschrift

To a solution of 5.79 g of 3,4-dihydroxylphenyl acetic acid ethyl ester dissolved in dry acetone were added 4.48 g of potassium carbonate and 4.15 ml of benzyl bromide. The mixture was heated to reflux until the starting materials were exhausted; and then the solvent was distilled off under reduced pressure. To the residues thus obtained was added 50 ml of water; and the mixture was acidified with concentrated hydrochloric acid and extracted with dichloromethane. The organic layer was dried over magnesium sulfate and evaporated under reduced pressure to obtain residues, which were purified by chromatography to provide 3.80 g (yield 45%) of 3-benzyloxy-4-hydroxyphenylacetic acid ethyl ester, having the characteristics of: NMR(CDCl3, 200 MHz) δ1.24(t, J=7 Hz, 3H, CH3), 3.45(s, 2H, CH2CO), 4.12(q, J=7 Hz, 2H, OCH2), 5.05(s, 2H, CH2Ph), 6.77-7.35(m, 6H, ArH).

Quelle