Reaktion #4979

Reaktionsgleichung

4-Methylresorcinol

succinic anhydride

→

powder

Ausbeute 74.2%

9-Carboxyethylidene-3,6-dihydroxy-2,7-dimethyl-9H-xanthene

Ausbeute 74.2%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe flask was purged with nitrogen
2. 2
   workup.ADDITIONMethanesulfonic acid (150 mL) was added
3. 3
   workup.ADDITIONThe solution was added dropwise to 1 L
4. 4
   Temperaturice-cooled water
5. 5
   workup.ADDITIONwith the simultaneous addition of 50% aq sodium hydroxide
6. 6
   Temperaturto maintain the pH at 2.25 +/-0.25
7. 7
   SonstigeThe product was collected by centrifugation
8. 8
   Waschenwashed with water (3×) and acetone (2×)
9. 9
   SonstigeThe solid was air-dried
10. 10
    Sonstigevacuum-dried at 110° C.

Vorschrift

4-Methylresorcinol (25.8 g, 0.208 mol) and succinic anhydride (20.8 g, 0.208 g) were placed in a round bottom flask and the flask was purged with nitrogen. Methanesulfonic acid (150 mL) was added and the solution heated under nitrogen to 65° C. for 2 hours. The solution was added dropwise to 1 L of rapidly stirred, ice-cooled water with the simultaneous addition of 50% aq sodium hydroxide to maintain the pH at 2.25 +/-0.25. The product was collected by centrifugation and washed with water (3×) and acetone (2×). The solid was air-dried, then vacuum-dried at 110° C. to afford a brick-red powder (24.1 g, 74%).

Quelle