Br[C:2]1[CH:7]=[C:6]([C:8]([CH3:11])([CH3:10])[CH3:9])[CH:5]=[C:4]([C:12]([CH3:15])([CH3:14])[CH3:13])[CH:3]=1.C([Li])(C)(C)C.[Br-].[Mg+2].[Br-].Br[C:25]1[CH2:26][C:27]2[C:32]([CH:33]=1)=[CH:31][CH:30]=[CH:29][CH:28]=2>CCOCC>[C:12]([C:4]1[CH:3]=[C:2]([C:25]2[CH2:33][C:32]3[C:27]([CH:26]=2)=[CH:28][CH:29]=[CH:30][CH:31]=3)[CH:7]=[C:6]([C:8]([CH3:11])([CH3:10])[CH3:9])[CH:5]=1)([CH3:15])([CH3:14])[CH3:13]1-Bromo-3,5-di-t-butylbenzene (47.2 g, 0.175 mol) was dissolved in ether (500 mL) and cooled to −70° C. t-Butyllithium (200 mL of 1.7 M solution in pentane, 0.34 mol) was added at −70° C. over a two hour period. The solution was allowed to warm to room temperature slowly. Magnesium bromide etherate (46.5 g, 0.18 mol) was added and the slurry was stirred for one hour. The mixture was then cooled to 5° C. and 2-bromoindene (34.2 g, 0.18 mol) was added. The mixture was warmed to room temperature and then refluxed for three hours. The solution was cooled to room temperature and the reaction was quenched carefully with water. The layers were separated and the organics washed with salt brine and dried over magnesium sulfate. The solvents were evaporated and the product was distilled twice and recrystallized from hexane to give 37.1 g of product (70%).
Wird geladen…