反应详情

A solution of 3′-bromo-2-methoxybiphenyl (1.08 g, 4.1 mmol) in anhydrous tetrahydrofuran (10 mL) was stirred at −78° C. and 2.5M n-butyllithium in hexanes (1.64 mL, 4.1 mmol) was added at such a rate that the temperature did nor exceed −70° C. Stirring was continued at −78° C. for 1 hr. A solution of 25 (1.5 g, 4.1 mmol) in tetrahydrofuran (6 mL) was added at such a rate that the temperature did not exceed −65° C. Stirring was continued at −78° C. for 20 min and at room temperature for 2 hr. The reaction mixture was poured onto saturated ammonium chloride (150 mL) and extracted with ethyl acetate (150 mL). The organic extract was washed with water (2×80 mL). The organic layer was dried over sodium sulfate, filtered and the solvent was removed on a rotary evaporator. The crude product was purified by chromatography on silica (80 g) with 2% ethyl acetate in heptane (4 L). Pure 26 (0.87 g) and slightly impure 26 (0.38 g) were isolated (total yield 55%).

1. customexceed −70° C
2. customdid not exceed −65° C
3. stirringStirring
4. waitwas continued at −78° C. for 20 min and at room temperature for 2 hr
5. extractionextracted with ethyl acetate (150 mL)
6. extractionThe organic extract
7. washwas washed with water (2×80 mL)
8. dry with materialThe organic layer was dried over sodium sulfate
9. filtrationfiltered
10. customthe solvent was removed on a rotary evaporator
11. customThe crude product was purified by chromatography on silica (80 g) with 2% ethyl acetate in heptane (4 L)