反应详情

To 10.00 g (51 mmol) of methyl 3,4 dimethoxybenzoate (6) in 50 mL of AcOH at 0° C. was added 8.90 g (56 mmol) of Br2 in 50 mL of AcOH over 1.5 h. The ice bath was removed and the mixture stirred 45 min. The reaction was quenched by pouring into 700 mL of H2O, stirred 30 min, left quiescent for 1 h, and filtered. The collected solid was washed with H2O and washed with sat. aq. Na2S2O3. The solid was partially dried, dissolved in 300 mL hot MeOH, and the resultant solution was cooled. The cool methanolic solution of product was treated with 200 mL of H2O and the white solid filtered to give 8.92 g (64% yield) of methyl-2-bromo-4,5-dimethoxybenzoate (7) as a white powder. The compound matched the physical and spectral properties of the known compound.

1. customThe ice bath was removed
2. customThe reaction was quenched
3. additionby pouring into 700 mL of H2O
4. stirringstirred 30 min
5. waitleft quiescent for 1 h
6. filtrationfiltered
7. washThe collected solid was washed with H2O
8. washwashed with sat. aq. Na2S2O3
9. customThe solid was partially dried
10. dissolutiondissolved in 300 mL hot MeOH
11. temperaturethe resultant solution was cooled
12. additionThe cool methanolic solution of product was treated with 200 mL of H2O
13. filtrationthe white solid filtered