Reaktion #69454

Reaktionsgleichung

HCl

methyl 3-bromo-4-hydroxybenzoate

triethylamine

1-(vinyloxy)butane

→

methyl 3-acetyl-4-hydroxybenzoate

Ausbeute 82.0%

Lösungsmittel

ether

DCM

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction was cooled down
2. 2
   Filtrationfiltered
3. 3
   Einengenthe filtrate concentrated
4. 4
   workup.ADDITIONwas added
5. 5
   workup.STIRRINGStirring
6. 6
   Temperaturwas maintained for 2 h
7. 7
   Sonstigethe organic phase was separated
8. 8
   Trocknendried over MgSO4
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated
11. 11
    Sonstigeto afford a solid which
12. 12
    FiltrationThe solid was filtered off
13. 13
    Einengenthe filtrate concentrated to dryness

Vorschrift

To a degassed solution of methyl 3-bromo-4-hydroxybenzoate (350 g, 1514.87 mmol) in ethanol (3 L) were added triethylamine (0.528 L, 3787.17 mmol), 1-(vinyloxy)butane (0.588 L, 4544.60 mmol), 1,1′-bis(diphenylphosphino)ferrocene (33.1 g, 60.6 mmol) and diacetoxypalladium (8.50 g, 37.9 mmol) under nitrogen. The mixture was heated at 70° C. overnight. The reaction was cooled down, filtered and the filtrate concentrated. The resulting solid was solubilized with DCM (2 L) and HCl 4N (1.14 L, 4544 mmol) was added under stirring. Stirring was maintained for 2 h, the organic phase was separated, dried over MgSO4, filtered and concentrated to afford a solid which was stirred in ether (5 L) for 2 h. The solid was filtered off and the filtrate concentrated to dryness to afford methyl 3-acetyl-4-hydroxybenzoate (240 g, 82%) as a beige powder. Mass spectrum: m/z [M−H]−=193.

Quelle