Reaktion #54130

Reaktionsgleichung

phosgene

L-valine

→

(S)-4-Isopropyl-oxazolidine-2,5-dione

Ausbeute 47.3%

Lösungsmittel

toluene

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter the complete addition the mixture
2. 2
   SonstigeThen a stream of nitrogen was bubbled through the solution
3. 3
   Sonstigefor 20 min.
4. 4
   Sonstigewas evaporated
5. 5
   SonstigeRecrystallization of the obtained residue from PE/Ether (2:1)

Vorschrift

30.4 ml (57.47 mmol, 1.08 eq.) of a 20% solution of phosgene in toluene were added slowly at r.t. to a stirred solution of 6.26 g (53.44 mmol) L-valine (81a) in 63 ml dry THF. After the complete addition the mixture was heated at 55° C. for 4 h. Then a stream of nitrogen was bubbled through the solution and passed after that through a 1M aq. NaOH-solution for 20 min. before the solvent was evaporated. Recrystallization of the obtained residue from PE/Ether (2:1) yielded 3.62 g (25.29 mmol, 47.32%) (S)-4-Isopropyl-oxazolidine-2,5-dione (86) as a white solid.

Quelle