反応 #684944

反応方程式

2,5-Dibromohydroquinone

sodium hydroxide

dodecylbromide

→

2,5-Dibromo-4-dodecyloxy phenol

収率 60.0%

溶媒

ethanol

反応条件

後処理

1. 1
   温度the reaction mixture was cooled
2. 2
   その他the precipitate formed
3. 3
   ろ過was filtered
4. 4
   洗浄washed with methanol
5. 5
   その他The filtrate was evaporated
6. 6
   その他to remove the solvent
7. 7
   workup.ADDITION2 L of distilled water was added to the residue
8. 8
   workup.WAITboiled gently for 1 h
9. 9
   温度cooled
10. 10
    ろ過The resulting precipitate was collected by filtration
11. 11
    洗浄washed with water
12. 12
    その他dried in vacuo
13. 13
    その他The crude product was purified by column chromatography
14. 14
    workup.ADDITIONa mixture of solvents (CH2Cl2:hexanes, 4:6)
15. 15
    その他to get the pure product in 60% yield

実験手順

2,5-Dibromohydroquinone 3 (40.2 g, 0.15 mol) was dissolved in a solution of sodium hydroxide (9.2 g, 0.23 mol) in 1.5 L of absolute ethanol at room temperature under nitrogen atmosphere. The reaction mixture was warmed to 50-60° C. with constant stirring. The dodecylbromide (36 ml, 0.15 mol) was added drop wise to the above reaction mixture at 60° C. After 10 h of stirring under nitrogen atmosphere, the reaction mixture was cooled and the precipitate formed was filtered and washed with methanol. This precipitate was identified as dialleylated-2,5-dibromohydroquinone as a side product. The filtrate was evaporated to remove the solvent. 2 L of distilled water was added to the residue and the mixture was acidified with 36% HCl, boiled gently for 1 h and cooled. The resulting precipitate was collected by filtration, washed with water and dried in vacuo. The crude product was purified by column chromatography using a mixture of solvents (CH2Cl2:hexanes, 4:6) to get the pure product in 60% yield.

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