反応 #7496

反応方程式

methanesulfonic acid

ethyl 4-oxocyclohexanecarboxylate

sodium bicarbonate

sodium azide

→

ester

収率 70.0%

ethyl 7-oxo-4-azepanecarboxylate

収率 70.0%

溶媒

CHCl3

反応条件

後処理

1. 1
   温度with reflux condenser, magnetic stirrer
2. 2
   workup.DISSOLUTIONdissolved in 20 ml of over 30 min
3. 3
   温度The mixture was heated
4. 4
   温度to reflux for 1 hour
5. 5
   その他the mixture decanted
6. 6
   抽出the aqueous phase extracted with 3×150 ml of CHCl3
7. 7
   乾燥the combined organic phases were dried over magnesium sulfate
8. 8
   ろ過filtered
9. 9
   濃縮concentrated to dryness
10. 10
    その他The residue was purified by PrepLC (800 g SiO2, CH2Cl2/MeOH, 97/3)
11. 11
    その他to give 5.1 g of crude compound
12. 12
    その他It was crystallised from 40 ml of diethylether

実験手順

In a 250 ml three necked flask fitted with reflux condenser, magnetic stirrer and dropping funnel under inert atmosphere, 5.6 ml (5.98 g, 34 mmoles, 1 eq) of ethyl 4-oxocyclohexanecarboxylate 27 were dissolved in 50 ml of CHCl3. 6.65 g (102 mmole, 3 eq) of sodium azide were added, followed by 22.1 ml (32.8 g, 341 mmoles, 10 eq) of methanesulfonic acid dissolved in 20 ml of over 30 min. The mixture was heated to reflux for 1 hour and cooled down to 10° C. 200 nl of saturated sodium bicarbonate solution were added, the mixture decanted and the aqueous phase extracted with 3×150 ml of CHCl3, the combined organic phases were dried over magnesium sulfate, filtered and concentrated to dryness. The residue was purified by PrepLC (800 g SiO2, CH2Cl2/MeOH, 97/3) to give 5.1 g of crude compound. It was crystallised from 40 ml of diethylether to give 4.41 g of pure ester 28, 70% yield.

出典