反应详情

To a mixture of magnesium turnings (3.0 g, 0.12 mol), anhydrous THF (20 mL) and a small amount of iodine in a 300 mL flask, a solution of 2-ethylhexylbromide (23.5 g, 0.12 mol) in anhydrous THF (35 mL) was added slowly at 0° C. under N2. After refluxing for 1 h, the solution was added dropwise to a mixture of 3-bromothiophene (15 g, 0.09 mol, (9-3)), Ni(dppp)Cl2 (0.51 g, 0.001 mmol) and anhydrous THF (35 mL) placed in a 500 mL flask at 0° C. After the mixture was stirred overnight at room temperature, the reaction was quenched by pouring cold HCl aq. (2 N) into the mixture. The product was extracted with CHCl3 and dried over anhydrous Mg2SO4. The crude product was further purified by column chromatography using hexane as the eluent to give (9-4) as a clear liquid (11 g, 61%). 1H NMR (CDCl3, 300 MHz, ppm): 7.20-7.22 (m, 1H), 6.88-6.90 (m, 2H), 2.56 (d, 2H, J=6.9 Hz), 1.49-1.57 (m, 1H), 1.24-1.33 (m, 8H), 0.86-0.89 (m, 6H)

1. temperatureAfter refluxing for 1 h
2. customplaced in a 500 mL flask at 0° C
3. customthe reaction was quenched
4. additionby pouring cold HCl aq. (2 N) into the mixture
5. extractionThe product was extracted with CHCl3
6. dry with materialdried over anhydrous Mg2SO4
7. customThe crude product was further purified by column chromatography