Reaktion #2664

Reaktionsgleichung

product

3-formyl-6-hydroxy-5-methoxy benzonitrile

boron tribromide

→

expected product

Ausbeute 72.4%

3-formyl-5,6-dihydroxy benzonitrile

Ausbeute 72.4%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITthe mixture stood for one night at ambient temperature
2. 2
   EinengenIt was concentrated
3. 3
   Temperaturcooled again to 0° C.
4. 4
   workup.ADDITION250 ml of a normal solution of hydrochloric acid were added
5. 5
   SonstigeThe crystallized product was separated out
6. 6
   Waschenwashed with water
7. 7
   Sonstigedried
8. 8
   Sonstigethen crystallized from an isopropanol

Vorschrift

18 g of the product of Step A and 400 ml of dichloromethane were mixed together under nitrogen and the mixture was cooled to 0° C. 150 ml of a molar solution of boron tribromide in dichloromethane were added and the mixture stood for one night at ambient temperature. It was concentrated, cooled again to 0° C. and 250 ml of a normal solution of hydrochloric acid were added. The crystallized product was separated out, washed with water, dried then crystallized from an isopropanol--water mixture (1-2) to obtain 12 g of the expected product.

Quelle