Réaction #361636

Équation de réaction

4-hydroxy-5-methoxy-isophthalaldehyde

hydrobromic acid

→

4,5-dihydroxyisophthalaldehyde

Solvants

Conditions de réaction

Traitement

1. 1
   Températureheated
2. 2
   Températureunder reflux
3. 3
   workup.ADDITIONare added
4. 4
   Filtrationthe separated precipitate is filtered under suction
5. 5
   Lavagewashed with water
6. 6
   Filtrationfiltered over 50 g of aluminum oxide (activity grade II)
7. 7
   AutreThe crystalline material obtained
8. 8
   Autreis recrystallized from ethyl acetate/n-hexane

Mode opératoire

5.0 g of 4-hydroxy-5-methoxy-isophthalaldehyde are treated with 50 ml of constant-boiling hydrobromic acid and heated to boiling under reflux and while stirring under an argon atmosphere for 3 hours. After cooling 50 ml of ice-water are added thereto, and the separated precipitate is filtered under suction and washed with water. The crude product is taken up in ethyl acetate and filtered over 50 g of aluminum oxide (activity grade II). The crystalline material obtained is recrystallized from ethyl acetate/n-hexane. There is obtained 4,5-dihydroxyisophthalaldehyde in the form of slightly orange crystals of m.p. 201°-202°.

Source