反応 #7497

反応方程式

sodium hydride

ethyl 7-oxo-4-azepanecarboxylate

tert-butyl 2-bromobutanoate

→

diester

収率 94.4%

ethyl 1-[1-(tert-butoxycarbonyl)propyl]-7-oxo-4-azepanecarboxylate

収率 94.4%

溶媒

acetonitrile

反応条件

後処理

1. 1
   温度with reflux condenser, magnetic stirrer
2. 2
   濃縮concentrated to dryness
3. 3
   workup.ADDITIONthe residue was poured on ice/water and neutralised with solid ammonium chloride
4. 4
   抽出The mixture was extracted three times with CH2Cl2
5. 5
   乾燥the combined organic phases were dried over magnesium sulfate
6. 6
   ろ過filtered
7. 7
   濃縮concentrated to dryness
8. 8
   その他The residue was purified by PrepLC (1 kg SiO2, CH2Cl2/MTBE, 85/15)

実験手順

In a 150 ml three necked flask fitted with reflux condenser, magnetic stirrer and dropping funnel under inert atmosphere, 5.09 g (27.5 mmoles, 1 eq) of ethyl 7-oxo-4-azepanecarboxylate 28 and 12.27 g (55 mmoles, 2 eq) of tert-butyl 2-bromobutanoate were dissolved in 70 ml of acetonitrile. The temperature was raised to 50° C. and 1.32 g (55 mmoles, 2 eq) of sodium hydride were added portionwise (exothermic). The mixture was stirred one more hour at 50° C. and concentrated to dryness, the residue was poured on ice/water and neutralised with solid ammonium chloride. The mixture was extracted three times with CH2Cl2, the combined organic phases were dried over magnesium sulfate, filtered and concentrated to dryness. The residue was purified by PrepLC (1 kg SiO2, CH2Cl2/MTBE, 85/15) to give 8.5 g of pure diester 29, 69% yield.

出典