반응 #7496

반응 방정식

methanesulfonic acid

ethyl 4-oxocyclohexanecarboxylate

sodium bicarbonate

sodium azide

→

ester

수율 70.0%

ethyl 7-oxo-4-azepanecarboxylate

수율 70.0%

용매

CHCl3

반응 조건

후처리

1. 1
   온도with reflux condenser, magnetic stirrer
2. 2
   workup.DISSOLUTIONdissolved in 20 ml of over 30 min
3. 3
   온도The mixture was heated
4. 4
   온도to reflux for 1 hour
5. 5
   기타the mixture decanted
6. 6
   추출the aqueous phase extracted with 3×150 ml of CHCl3
7. 7
   건조the combined organic phases were dried over magnesium sulfate
8. 8
   여과filtered
9. 9
   농축concentrated to dryness
10. 10
    기타The residue was purified by PrepLC (800 g SiO2, CH2Cl2/MeOH, 97/3)
11. 11
    기타to give 5.1 g of crude compound
12. 12
    기타It was crystallised from 40 ml of diethylether

실험 절차

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.

출처