Reaktion #593050

Reaktionsgleichung

1,3-oxazolidine-2,4-dione

1,1,3,3-tetramethylguanidine

1,1-dimethylethyl 4-{[(methylsulphonyl)oxy]methyl}piperidine-1-carboxylate

→

1,1-dimethylethyl 4-[(2,4-dioxo-1,3-oxazolidin-3-yl)methyl]piperidine-1-carboxylate

Lösungsmittel

tetrahydrofuran

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeprepared in step 2.1
2. 2
   Temperaturis heated
3. 3
   Temperaturat reflux for 24 hours
4. 4
   Sonstigeto return to ambient temperature
5. 5
   Einengenis concentrated under reduced pressure
6. 6
   Sonstigewater and the aqueous phase is separated off
7. 7
   Extraktionextracted twice with dichloromethane
8. 8
   WaschenThe combined organic phases are washed with saturated aqueous sodium chloride solution
9. 9
   Trocknendried over sodium sulphate
10. 10
    Sonstigeevaporation of the solvent
11. 11
    Sonstigethe residue obtained
12. 12
    Sonstigeis purified by chromatography on silica gel
13. 13
    Wascheneluting with a 98/2
14. 14
    workup.ADDITION95/5 mixture of dichloromethane and methanol

Vorschrift

A suspension of 13.60 g (46.36 mmol) of 1,1-dimethylethyl 4-{[(methylsulphonyl)oxy]methyl}piperidine-1-carboxylate, prepared in step 2.1., 9.37 g (92.72 mmol) of 1,3-oxazolidine-2,4-dione and 16.02 g (139.08 mmol) of 1,1,3,3-tetramethylguanidine in a mixture of 180 ml of tetrahydrofuran and 30 ml of dimethylformamide is heated at reflux for 24 hours. It is allowed to return to ambient temperature and is concentrated under reduced pressure. The residue is taken up in dichloromethane and water and the aqueous phase is separated off and extracted twice with dichloromethane. The combined organic phases are washed with saturated aqueous sodium chloride solution and dried over sodium sulphate. Following evaporation of the solvent, the residue obtained is purified by chromatography on silica gel, eluting with a 98/2 then 95/5 mixture of dichloromethane and methanol.

Quelle