反应详情

A solution of 2',3'-dimethoxyacetophenone (4.85 g, 26.9 mmol) in dichloromethane (100 ml) was added at -70° C. with a 1M boron tribromide solution in dichloromethane (68 ml). The mixture was left to cool, keeping stirring for 2.5 hours at room temperature, then added with methanol (70 ml), left under stirring for 1 h, thereafter evaporated to dryness. The residue was dissolved in ethyl acetate (250 ml), washed with 2% NaHCO3 (1×30 ml), dried and the solvent was evaporated off, to obtain a crude which was purified by crystallization in methanol, thereby obtaining 3.10 g of the title compound as a yellow solid (76% yield).

1. waitThe mixture was left
2. temperatureto cool
3. waitleft
4. stirringunder stirring for 1 h
5. customevaporated to dryness
6. dissolutionThe residue was dissolved in ethyl acetate (250 ml)
7. washwashed with 2% NaHCO3 (1×30 ml)
8. customdried
9. customthe solvent was evaporated off
10. customto obtain a crude which
11. customwas purified by crystallization in methanol