반응 #10714

반응 방정식

water

Benzo[b]thiophene-2-boronic acid

sodium carbonate

5-bromo-2,4-dimethoxybenzaldehyde

→

5-(benzo[b]thien-2-yl)-2,4-dimethoxybenzaldehyde

수율 83.0%

용매

ethylene glycol dimethyl ether

반응 조건

후처리

1. 1
   workup.STIRRINGThe mixture was stirred
2. 2
   온도at reflux under nitrogen for 24 hours
3. 3
   온도Upon cooling to room temperature
4. 4
   추출extracted with ethyl acetate
5. 5
   건조The organic phase was dried over sodium sulfate
6. 6
   기타evaporated

실험 절차

Ex-3A: A sample of 5-bromo-2,4-dimethoxybenzaldehyde (4.9 g, 20.0 mmol) was dissolved in ethylene glycol dimethyl ether (50 mL). Tetrakis(triphenylphosphine)palladium(0) (2.32 g, 2 mmol) was added, and the mixture was stirred at room temperature under nitrogen for 5 min. Benzo[b]thiophene-2-boronic acid (4.27 g, 24 mmol) and sodium carbonate solution (2 M, 20 mL) were added. The mixture was stirred at reflux under nitrogen for 24 hours. Upon cooling to room temperature, the mixture was poured into water and extracted with ethyl acetate. The organic phase was dried over sodium sulfate and evaporated. Silica gel chromatography (hexane/ethyl acetate 2:1 then 1:1) gave 4.75 g (83%) of the desired 5-(benzo[b]thien-2-yl)-2,4-dimethoxybenzaldehyde. 1H NMR (CDCl3) δ 10.36 (s, 1H), 8.20 (s, 1H), 7.83–7.78 (m, 2H), 7.68 (s, 1H), 7.36–7.27 (m, 2H), 6.54 (s, 1H), 4.06 (s, 3H), 4.00 (s, 3H).

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