反应详情

Add (4.23 g, 19.47 mmol) 1-bromo-2,4-dimethoxybenzene to an appropriately sized round bottom flask. Attach a rubber septum to seal the flask. Insert a needle into the septum as a vent and flush the round bottom flask with nitrogen for about 10 minutes. Add anhydrous ether (80 mL), followed by the drop wise addition of n-butyllithium in hexane (1.6M, 12.2 mL). Stir the cloudy mixture for 10 minutes and keep the round bottom flask on ice. Dissolve (2.20 g, 9.74 mmol) of methyl 2,4-dimethoxybenzoate in about 20 ml of anhydrous ether (if needed, more than about 20 ml can be used), and then add this drop wise to the reaction mixture. After the addition is complete, stir the reaction mixture for about 3 minutes longer. Pour the reaction mixture into a separatory funnel containing 5% NH4Cl (aq) (50 mL) and shake until a color change is observed (pale orange). The layers are allowed to separated, and dry the top ether layer with about 5 g anhydrous Na2SO4, filter, and the volatiles were removed in a rotary evaporator to dryness at 35-40° C. under 400 mbar. Place the crude oil of hexamethoxy red (yellow-orange in color) into the freezer. Yield is about 3.1 g.

1. customto seal the flask
2. customInsert a needle into the septum as a vent and flush the round bottom flask with nitrogen for about 10 minutes
3. additionAdd anhydrous ether (80 mL), followed by the drop wise addition of n-butyllithium in hexane (1.6M, 12.2 mL)
4. additionadd this drop wise to the reaction mixture
5. additionAfter the addition
6. stirringstir the reaction mixture for about 3 minutes longer
7. additionPour the reaction mixture into a separatory funnel
8. customto separated
9. dry with materialdry the top ether layer with about 5 g anhydrous Na2SO4
10. filtrationfilter
11. customthe volatiles were removed in a rotary evaporator to dryness at 35-40° C. under 400 mbar