反应详情

4.8 ml of boron tribromide dissolved in 20 ml of methylene chloride are added dropwise while cooling with ice within 20 minutes to 4.0 g of hexyl (3-cyano-4,5-dimethoxyphenyl)glyoxylate dissolved in 100 ml of methylene chloride and the reaction mixture is stirred at room temperature for 18 hours. 40 ml of methanol are subsequently added dropwise thereto at -60°, the mixture is stirred at room temperature for 1 hour and evaporated. The residue is taken up in methanol. It is heated under reflux for 10 minutes, evaporated to dryness and dried in a high vacuum. The thus-obtained crude product is recrystallized from acetonitrile. There is obtained methyl (3-cyano-4,5-dihydroxyphenyl)glyoxylate of m.p. 252°.

1. additionare added dropwise
2. stirringat -60°, the mixture is stirred at room temperature for 1 hour
3. customevaporated
4. temperatureIt is heated
5. temperatureunder reflux for 10 minutes
6. customevaporated to dryness
7. customdried in a high vacuum
8. customThe thus-obtained crude product
9. customis recrystallized from acetonitrile