反应详情

A mixture of zinc (404 mg, 6.17 mmol) and lithium chloride (261 mg, 6.17 mmol) under argon was warmed for 15 minutes using a hot air gun, allowed to cool and then anhydrous THF (20 mL) added. The zinc was activated by treatment with 1,2-dibromoethane (19 mg, 0.10 mmol) and TMSCl (2.2 mg, 0.02 mmol). To the resulting mixture at 25° C. was added ethyl 4-(bromomethyl)benzoate (500 mg, 2.06 mmol) and the mixture stirred for 15 minutes. A solution of 3,4-dichloro-iodobenzene (392 mg, 1.44 mmol) in anhydrous THF (5 mL) was added, followed by (1,3-bis(2,6-diisopropylphenyl)imidazolidene)(3-chloropyridyl)palladium(II) dichloride [PEPPSI™-SlP] (14 mg, 0.02 mmol) and the mixture stirred at 25° C. for 1 hour. Saturated ammonium chloride solution was added and the crude product extracted with ether. The ether extract was washed with brine, dried over Na2SO4 and the solvent evaporated in vacuo. The crude product was purified by silica gel column chromatography eluting with 7:3 hexane:ethyl acetate to afford the title compound (240 mg, 38%).

1. temperaturewas warmed for 15 minutes
2. temperatureto cool
3. stirringthe mixture stirred at 25° C. for 1 hour
4. extractionthe crude product extracted with ether
5. extractionThe ether extract
6. washwas washed with brine
7. dry with materialdried over Na2SO4
8. customthe solvent evaporated in vacuo
9. customThe crude product was purified by silica gel column chromatography
10. washeluting with 7:3 hexane