반응 #10713

반응 방정식

thiophene-2-boronic acid

5-bromo-3,4-dimethoxybenzaldehyde

→

3,4-dimethoxy-5-(thien-2-yl)benzaldehyde

수율 91.0%

용매

ethylene glycol dimethyl ether

반응 조건

후처리

1. 1
   온도The reaction was refluxed for 16 h
2. 2
   농축The reaction mixture was concentrated
3. 3
   workup.ADDITIONdiluted with an aqueous solution of saturated sodium bicarbonate (75 mL)
4. 4
   추출extracted with dichloromethane (2×100 mL)
5. 5
   건조The organic layer was dried over sodium sulfate
6. 6
   농축concentrated to a brown solid
7. 7
   기타The crude material was purified by silica gel chromatography (1:1 ethyl acetate/hexanes)

실험 절차

Ex-1D: A solution of 5-bromo-3,4-dimethoxybenzaldehyde (10.23 g, 41.7 mmol) in 359 mL of ethylene glycol dimethyl ether was purged with nitrogen gas for 30 min. The solution was treated with tetrakis(triphenylphosphine)palladium(0) (5.0 g, 4.3 mmol), thiophene-2-boronic acid (8.01 g, 62.6 mmol), and a solution of 2 N sodium carbonate 72 mL, 3.45 mmol). The reaction was refluxed for 16 h. The reaction mixture was concentrated, diluted with an aqueous solution of saturated sodium bicarbonate (75 mL), and extracted with dichloromethane (2×100 mL). The organic layer was dried over sodium sulfate and concentrated to a brown solid. The crude material was purified by silica gel chromatography (1:1 ethyl acetate/hexanes) to give 9.42 g (90%) of the desired 3,4-dimethoxy-5-(thien-2-yl)benzaldehyde product. 1H-NMR (300 MHz, CDCl3) δ 9.94 (s, 1H), 7.79 (d, 1H), 7.57 (dd, 1H), 7.41 (d, 1H), 7.36 (d, 1H), 7.13 (dd, 1H), 3.97 (s, 3H), 3.93 (s, 3H).

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