反応 #2128650

反応方程式

3,3-dimethyl-bromobutane

4-cyanobenzaldehyde

iodine

3,3-dimethyl-bromobutane

3,3-dimethyl-bromobutane

→

desired intermediate

収率 62.5%

4-(4,4-Dimethyl-pentanoyl)-benzonitrile

収率 62.5%

溶媒

THF

THF

反応条件

後処理

1. 1
   その他for 2 h
2. 2
   その他Purge the flask with nitrogen/vacuo several times
3. 3
   workup.ADDITIONAdd
4. 4
   温度reflux the mixture overnight
5. 5
   温度reflux for 30 min
6. 6
   温度Warm the flask gradually to room temperature overnight
7. 7
   その他Quench the mixture with 0.1M aqueous HCl (100 mL)
8. 8
   抽出extract twice with EtOAc
9. 9
   乾燥Dry the combined organic extracts over Na2SO4
10. 10
    ろ過filter
11. 11
    濃縮concentrate in vacuo
12. 12
    その他Purify the crude mixture by chromatography on silica gel eluting with hexane/EtOAc (19:1)

実験手順

Keep Mg turnings (402 mg, 15.251 mmol) in vacuo in a two-neck round bottom flask for 2 h. Purge the flask with nitrogen/vacuo several times. Add a couple crystals of iodine, anhydrous THF (60 mL) and 3,3-dimethyl-bromobutane (0.8 mL, 5.59 mmol) slowly (exothermic reaction observed). Add dropwise the remaining 3,3-dimethyl-bromobutane (1.6 mL, 11.18 mmol) and reflux the mixture overnight. Add some additional 3,3-dimethyl-bromobutane (0.24 mL, 1.67 mmol) and reflux for 30 min. Cool the mixture to −10° C. and add a solution of 4-cyanobenzaldehyde (4 g, 30.502 mmol) in anhydrous THF (40 mL). Warm the flask gradually to room temperature overnight. Quench the mixture with 0.1M aqueous HCl (100 mL) and extract twice with EtOAc. Dry the combined organic extracts over Na2SO4, filter and concentrate in vacuo. Purify the crude mixture by chromatography on silica gel eluting with hexane/EtOAc (19:1) to give the desired intermediate as an oil (0.752 g, 23%).

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