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

Participants

Reaction Conditions

Reaction Steps

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 1L 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%).

Provenance & Evidence