反应详情

5-(2-Methoxyphenyl)-1,3-cyclohexanedione (15.0 g) was suspended in methylene chloride (150 ml). The mixture was cooled to -78° with stirring and a solution of boron tribromide (39.3 g) in methylene chloride (75 ml) was added dropwise over 1h. The mixture was stirred at -78° for 45 min after the addition was complete and at room temperature for a further 18h. Excess water was added and the mixture was stirred vigorously at room temperature for 4h. The solid which separated out was collected by filtration, washed with water and dried to afford the title dione (12.0 g). Recrystallisation from aqueous ethanol afforded white prisms m.p. 190°-192°.

1. temperatureThe mixture was cooled to -78°
2. stirringThe mixture was stirred at -78° for 45 min
3. additionafter the addition
4. stirringthe mixture was stirred vigorously at room temperature for 4h
5. customThe solid which separated out
6. filtrationwas collected by filtration
7. washwashed with water
8. customdried
9. customto afford the title dione (12.0 g)
10. customRecrystallisation from aqueous ethanol afforded white prisms m.p. 190°-192°