反应详情

Under nitrogen, ZnCl2 (0.5 M solution in tetrahydrofuran; 6.8 mL, 3.41 mmol) was added by syringe to a round-bottomed flask sealed with a rubber septum and purged with nitrogen. Hexyl magnesium chloride (1.0 M solution in THF; 4.0 mL, 4.26 mmol) was then added dropwise by syringe, and the resulting solution was stirred at room temperature for 20 minutes. Next, N-methylpyrrolidinone (4.7 mL) was added by syringe. After 5 minutes, 21.7 mg (0.0426 mmol) Pd(P(t-Bu)3)2 and 500 mg (2.13 mmol) of compound (3) were added. The flask was then fitted with a reflux condenser and heated under refluxed for 48 hours. The flask was then gradually cooled to room temperature, and 20 mL of a 1.0M aqueous HCl solution was added. The resulting mixture was extracted with diethyl ether and the ether extract was washed with water, then dried over anhydrous MgSO4 and concentrated under vacuum to give the crude product. Purification by flash chromatography on silica gel afforded analytically pure compound (4a): 1H NMR (300 MHz) (CDCl3): δ 7.36-6.80 (m, 8H), 3.90 (s, 3H), 2.71-2.66 (t, 2H), 1.74-1.67 (m, 2H), 1.42-1.33 (m, 6H), 1.01-0.97 (t, 3H).

1. customsealed with a rubber septum
2. custompurged with nitrogen
3. waitAfter 5 minutes
4. customThe flask was then fitted with a reflux condenser
5. temperatureheated
6. temperatureunder refluxed for 48 hours
7. temperatureThe flask was then gradually cooled to room temperature
8. extractionThe resulting mixture was extracted with diethyl ether
9. extractionthe ether extract
10. washwas washed with water
11. dry with materialdried over anhydrous MgSO4
12. concentrationconcentrated under vacuum
13. customto give the crude product
14. customPurification by flash chromatography on silica gel