反应详情

Solid 3a (5.50 g, 7.06 mmol) was added to an ice cold suspension of anhydrous FeCl3 (9.16 g, 56.5 mmol) in dry CH2Cl2 (250 mL). Within 2 min 1,4-dimethoxybenzene (3.90 g, 28.2 mmol) was added to the green reaction mixture. The reaction mixture was allowed to warm slowly to room temperature and then stir for an additional 12 h. The reaction mixture was quenched with anhydrous MeOH (30 mL). The volume of the mixture was reduced to 50 mL under reduced pressure and MeOH (200 mL) was added to the resulting oil. The slightly violet product was colled on a frit and washed with MeOH. The product was further purified by column chromatography using a 50% CH2Cl2/50% hexane solvent mixture to afford 4a (RF=0.24) as a colorless solid in 84% yield (mp 69-70° C.).

1. customThe reaction mixture was quenched with anhydrous MeOH (30 mL)
2. additionwas added to the resulting oil
3. washwashed with MeOH
4. customThe product was further purified by column chromatography