Potassium Carbonate → 4-Bromo-3-(3-methoxy-propoxy)-benzoic acid methyl ester

Reaktionsgleichung

[CH3:1][O:2][C:3](=[O:12])[C:4]1[CH:9]=[CH:8][C:7]([Br:10])=[C:6]([OH:11])[CH:5]=1.C(=O)([O-])[O-].[K+].[K+].I[CH2:20][CH2:21][CH2:22][O:23][CH3:24]>C(#N)C>[CH3:1][O:2][C:3](=[O:12])[C:4]1[CH:9]=[CH:8][C:7]([Br:10])=[C:6]([O:11][CH2:20][CH2:21][CH2:22][O:23][CH3:24])[CH:5]=1

Komponenten

Versuchsvorschrift

A solution of 4-bromo-3-hydroxy-benzoic acid methyl ester (12 g, 51.9 mmol), potassium carbonate (10.77 g, 77.9 mmol) and 1-iodo-3-methoxy propane (11.42 g, 57.1 mmol) in acetonitrile (250 mL) is stirred at reflux for 16 h. The solvent is concentrated under reduced pressure, H2O (100 mL) is added, and the aqueous layer extracted with ether (50 mL×4). The combined organic extracts are washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford the title which was used without further purification in the next step. TLC, Rf (hexane/AcOEt 2:1)=0.65. 1H-NMR (CDCl3, 300 MHz): δ=2.12 (p, 2H), 3.38 (s, 3H), 3.63 (t, 2H), 3.9 (s, 3H), 4.2 (t, 2H), 7.5 (d, 1H), 7.55 (m, 1H), 7.6 (d, 1H) ppm.