Réaction #7496

Équation de réaction

methanesulfonic acid

ethyl 4-oxocyclohexanecarboxylate

sodium bicarbonate

sodium azide

→

ester

Rendement 70.0%

ethyl 7-oxo-4-azepanecarboxylate

Rendement 70.0%

Solvants

CHCl3

Conditions de réaction

Traitement

1. 1
   Températurewith reflux condenser, magnetic stirrer
2. 2
   workup.DISSOLUTIONdissolved in 20 ml of over 30 min
3. 3
   TempératureThe mixture was heated
4. 4
   Températureto reflux for 1 hour
5. 5
   Autrethe mixture decanted
6. 6
   Extractionthe aqueous phase extracted with 3×150 ml of CHCl3
7. 7
   Séchagethe combined organic phases were dried over magnesium sulfate
8. 8
   Filtrationfiltered
9. 9
   Concentrationconcentrated to dryness
10. 10
    AutreThe residue was purified by PrepLC (800 g SiO2, CH2Cl2/MeOH, 97/3)
11. 11
    Autreto give 5.1 g of crude compound
12. 12
    AutreIt was crystallised from 40 ml of diethylether

Mode opératoire

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.

Source