反応 #7946

反応方程式

Bromine

9a-butyl-7-methoxy-8-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

CCl4

NaHCO3

→

4-bromo-9a-butyl-7-methoxy-8-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

収率 89.0%

溶媒

CH2Cl2

water

反応条件

後処理

1. 1
   温度was cooled in an ice bath
2. 2
   workup.STIRRINGwhile stirring
3. 3
   その他A gummy, red precipitate formed during the addition
4. 4
   workup.STIRRINGThe mixture was stirred
5. 5
   その他a total of 35 minutes
6. 6
   その他at 0° C
7. 7
   workup.STIRRINGshaken
8. 8
   その他The organic phase was separated
9. 9
   洗浄washed with water
10. 10
    workup.ADDITIONcontaining Na2S2O4
11. 11
    洗浄washed with brine
12. 12
    乾燥dried over MgSO4
13. 13
    ろ過filtered
14. 14
    その他evaporated under vacuum to a yellow gum (241 mg)
15. 15
    その他The crude product was purified by preparative layer chromatography on two 0.1×20×20 cm silica gel GF plates
16. 16
    洗浄The major UV visible band at Rf 0.39-0.50 was eluted with EtOAc
17. 17
    その他evaporated under vacuum

実験手順

A mixture of 9a-butyl-7-methoxy-8-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one (133 mg, 0.468 mmol), CCl4 (0.94 mL), and NaHCO3 (196 mg, 2.333 mmol) was cooled in an ice bath and stirred. Bromine (0.024 mL, 0.467 mmol) was added while stirring and swirling the reaction mixture by hand. A gummy, red precipitate formed during the addition. The mixture was swirled by hand for 5 minutes in order to break up the gum, which gradually changed to a stirrable orange solid. The mixture was stirred and swirled a total of 35 minutes at 0° C. The mixture was diluted with CH2Cl2 and water and shaken. The organic phase was separated, washed with water containing Na2S2O4, washed with brine, dried over MgSO4, filtered, and evaporated under vacuum to a yellow gum (241 mg). The crude product was purified by preparative layer chromatography on two 0.1×20×20 cm silica gel GF plates, developing with 4:1 hexanes-EtOAc. The major UV visible band at Rf 0.39-0.50 was eluted with EtOAc and evaporated under vacuum to give 4-bromo-9a-butyl-7-methoxy-8-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one (151 mg) as a white solid.

出典