Reaktion #69665

Reaktionsgleichung

benzyl bromide

acetone

5-bromo-2,4-dihydroxybenzoic acid

potassium carbonate

→

title compound

2,4-bis-benzyloxy-5-bromo-benzoic acid benzyl ester

Lösungsmittel

Water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigefitted with a flange lid
2. 2
   workup.ADDITIONcontaining stirrer
3. 3
   Sonstigetaken to 45° C
4. 4
   ExtraktionThe mixture was extracted with EtOAc (2×1 L)
5. 5
   workup.ADDITIONTo the residue was added Et2O (200 mL) and petroleum ether (1 L)
6. 6
   workup.STIRRINGthe mixture stirred for 30 min
7. 7
   Sonstigethe solid formed
8. 8
   Filtrationcollected by filtration
9. 9
   Sonstigedried in vacuo

Vorschrift

To a 10 L jacketed vessel, fitted with a flange lid containing stirrer, thermometer and dropping funnel, was charged acetone (2.5 L) followed by 5-bromo-2,4-dihydroxybenzoic acid (100 g, 0.43 mol) and potassium carbonate (356 g, 2.58 mol). To the stirring mixture at ambient was added benzyl bromide (185 mL, 1.55 mol) at a rate of ˜20 ml/min. The mixture was heated at 60° C. for 18 h and then taken to 45° C. Water (1.5 L) was added and the mixture stirred for 30 min. The mixture was extracted with EtOAc (2×1 L) and the combined organic portions reduced in vacuo. To the residue was added Et2O (200 mL) and petroleum ether (1 L), the mixture stirred for 30 min and the solid formed collected by filtration and dried in vacuo to give the title compound (197.2 g) as a white solid.

Quelle