Reaction #5486

Reaction equation

ammonium hydroxide

Methanesulfonic acid

2-Ethoxycarbonyl-cyclononanone

sodium azide

→

ethyl 2-oxo-1-azacyclodecane-10-carboxylate

Solvents

chloroform

Conditions

Workup

1. 1
   Temperatureheated
2. 2
   Temperatureto reflux for 4 hours
3. 3
   workup.ADDITIONThe reaction mixture is poured onto ice
4. 4
   Extractionextracted several times with methylene chloride
5. 5
   DryingThe combined organic layers are dried (MgSO4)
6. 6
   Otherthe solvent is evaporated
7. 7
   OtherThe product is purified by silica gel chromatography (40% ethyl acetate/hexane)

Procedure

2-Ethoxycarbonyl-cyclononanone (13.72 g, 64.7 mmol) is dissolved in chloroform (200 mL) and cooled to 0° C. Methanesulfonic acid (62.4 g, 650 mmol) is added, followed by sodium azide (12.68 g, 195 mmol). The reaction is stirred at room temperature for 30 minutes, and then heated to reflux for 4 hours. The reaction mixture is poured onto ice, made basic with concentrated ammonium hydroxide (pH=9), and extracted several times with methylene chloride. The combined organic layers are dried (MgSO4), and the solvent is evaporated. The product is purified by silica gel chromatography (40% ethyl acetate/hexane) to give ethyl 2-oxo-1-azacyclodecane-10-carboxylate, m.p. 101°-103° C.

Source