Reaktion #75983

Reaktionsgleichung

ethyl 2-(acetylamino)-3-(3-nitrophenyl)propanoate

ammonium hydrogen carbonate

water

→

ethyl (2R)-2-(acetylamino)-3-(3-nitrophenyl)propanoate

Ausbeute 50.0%

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITION0.017 g of type-II α-chymotrypsin is then introduced
2. 2
   workup.WAITthe mixture is left
3. 3
   workup.ADDITIONAfter this reaction time, the pH is less than 8, a further 0.017 g of type-II α-chymotrypsin is added
4. 4
   workup.STIRRINGstirring of the reaction medium
5. 5
   workup.WAITis continued for 2 hours 45 min
6. 6
   ExtraktionThe aqueous phase is extracted with 3 times 50 cm3 of ethyl acetate
7. 7
   Trocknenthe combined organic phases are then dried over sodium sulfate
8. 8
   Filtrationfiltered
9. 9
   Sonstigeevaporated under reduced pressure (2 kPa) at a temperature in the region of 40° C

Vorschrift

A mixture of 2.8 g of ethyl 2-(acetylamino)-3-(3-nitrophenyl)propanoate in 17 cm3 of acetonitrile [lacuna] to which is added 3.95 g of ammonium hydrogen carbonate and 35 cm3 of water at a pH in the region of 8. 0.017 g of type-II α-chymotrypsin is then introduced and the mixture is left stirring at room temperature for 1 hour 15 min, while measuring the pH regularly. After this reaction time, the pH is less than 8, a further 0.017 g of type-II α-chymotrypsin is added and stirring of the reaction medium is continued for 2 hours 45 min. The aqueous phase is extracted with 3 times 50 cm3 of ethyl acetate; the combined organic phases are then dried over sodium sulfate, filtered and evaporated under reduced pressure (2 kPa) at a temperature in the region of 40° C. 1.4 g of ethyl (2R)-2-(acetylamino)-3-(3-nitrophenyl)propanoate are obtained in the form of white crystals melting at 110° C.

Quelle