Reaktion #63568

Reaktionsgleichung

N-acetyl-3,5-dichloro-4-(4'-methoxy-3'-(6-methoxy-3-pyridylmethyl)-phenylthio)-α-carbethoxy-phenylalanine ethyl ester

boron tribromide

→

4-(4'-Hydroxy-3'-(6-oxo-3(1H)-pyridylmethyl) phenylthio)-3,5-dichlorophenylalanine

Ausbeute 70.0%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe mixture was stirred
2. 2
   workup.STIRRINGstirred for 5 hours
3. 3
   Temperaturrefluxed
4. 4
   Einengenwith concentrated hydrochloric in glacial acetic acid in a manner similar to

Vorschrift

To a cooled (-74°) solution of N-acetyl-3,5-dichloro-4-(4'-methoxy-3'-(6-methoxy-3-pyridylmethyl)-phenylthio)-α-carbethoxy-phenylalanine ethyl ester (0.39 g) in dry dichloromethane (10 ml) was added boron tribromide (0.58 ml) with stirring. The mixture was stirred whilst warming to room temperature and stirred for 5 hours. The reaction mixture was worked up and refluxed with concentrated hydrochloric in glacial acetic acid in a manner similar to that as described in Example 1 to afford DL-4-(4'-Hydroxy-3'-(6-oxo-3(1H)-pyridylmethyl) phenylthio)-3,5-dichlorophenylalanine as a cream solid (0.20 g, 70%), m.p. 261°-264°.

Quelle