反应详情

To a stirring solution of compound 1a (1.67 g, 3.5 mmol) in dry THF (30 mL) was added n-BuLi (2.5 M in hexane, 1.2 eq, 1.69 mL) dropwise over 10 min at −78° C. under a nitrogen atmosphere. This was stirred for 1 h at this temperature before adding a solution of compound 1c (0.72 g, 1 eq) in dry THF (10 mL) dropwise and stirred for 1 h at this temperature. The reaction mixture was allowed to warm to rt slowly and left stirring overnight. The reaction was quenched with a solution of saturated ammonium chloride solution (50 mL) and EA (250 mL). The organic layer was separated and the aq. layer was washed with EA (2×100 mL). The combined organic extracts were dried over sodium sulfate, filtered and concentrated to give the crude product as a brown oil. The product was isolated following CC with PE/EA (19:1 to 3:1). The reaction and purification was repeated twice on the same scale and the combined product (3.13 g) was repurified under the same conditions to afford the final product 1 (1.7 g, 19%). 1H NMR (CDCl3): 7.93 (m, 1H), 7.90-7.85 (m, 1H), 7.50-7.30 (m, 5H), 6.88 (s, 1H), 6.75-6.72 (m, 1H), 4.80 (s, 2H), 3.88 (s, 3H), 3.20-3.10 (m, 1H), 3.00-2.91 (m, 2H), 2.60-2.49 (m, 2H), 2.15-2.08 (m, 1H), 1.30-1.25 (m, 2H), 1.15-1.10 (m, 2H).

1. stirringstirred for 1 h at this temperature
2. waitleft
3. stirringstirring overnight
4. customThe reaction was quenched with a solution of saturated ammonium chloride solution (50 mL) and EA (250 mL)
5. customThe organic layer was separated
6. washthe aq. layer was washed with EA (2×100 mL)
7. dry with materialThe combined organic extracts were dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customto give the crude product as a brown oil
11. customThe product was isolated
12. customThe reaction and purification
13. customthe combined product (3.13 g) was repurified under the same conditions