Reaktion #10739

Reaktionsgleichung

Thiophene-2-boronic acid

potassium phosphate

trifluoro-methanesulfonic acid 2-formyl-5-methoxy-phenyl ester

→

4-methoxy-2-thiophen-2-yl-benzaldehyde

Ausbeute 90.0%

Lösungsmittel

1,4-dioxane

EtOAc

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturUpon cooling to room temperature the reaction
2. 2
   EinengenThe organic phase was concentrated under reduced pressure

Vorschrift

Ex-34B: A solution of trifluoro-methanesulfonic acid 2-formyl-5-methoxy-phenyl ester (Ex-34A, 1.6 g, 5.63 mmol) in 1,4-dioxane (15 mL) was stirred at room temperature under nitrogen for 5 min. Thiophene-2-boronic acid (1.08 g, 8.44 mmol), tetrakis(triphenylphosphine)palladium(0) (0.65 g, 0.56 mmol) and a potassium phosphate (2.2 g, 10.36 mmol) were then added and the resulting mixture was heated to 95° C. under nitrogen overnight. Upon cooling to room temperature the reaction was diluted with EtOAc (25 mL) and water (25 mL) and the layers were cut. The organic phase was concentrated under reduced pressure. Silica gel chromatography (hexane/ethyl acetate, 4:1) gave 1.1 g (90%) of the desired 4-methoxy-2-thiophen-2-yl-benzaldehyde product. 1H-NMR (300 MHz, CDCl3): 10.06 (s, 1H), 8.03 (m, 1H), 7.45 (m, 1H), 7.14 (m, 1H), 7.09 (m, 1H), 7.00 (m, 2H), 3.91 (s, 3H).

Quelle