反应详情

温度

10 °C

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.

1. temperaturewith reflux condenser, magnetic stirrer
2. dissolutiondissolved in 20 ml of over 30 min
3. temperatureThe mixture was heated
4. temperatureto reflux for 1 hour
5. customthe mixture decanted
6. extractionthe aqueous phase extracted with 3×150 ml of CHCl3
7. dry with materialthe combined organic phases were dried over magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated to dryness
10. customThe residue was purified by PrepLC (800 g SiO2, CH2Cl2/MeOH, 97/3)
11. customto give 5.1 g of crude compound
12. customIt was crystallised from 40 ml of diethylether