4-Aminobenzoic Acid → 4-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-methanoisoindol-2-yl)benzoic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To 4-aminobenzoic acid (800 g, 5.83 mol) is added dimethylacetamide (2.5 l), toluene (1 l), and slowly with stirring bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride (956 g, 5.83 mol). After the addition the mixture is stirred for 1 hour, raised to 140° C. with removal of water (100 ml) azeotropically and then raised to 165° C. to remove the toluene. The mixture is cooled and the product precipitated into water (3 l). Filtration, washing with water, drying in an oven at 80° C. and recrystallisation from ethanol yields a white crystalline solid (1.56 kg, 94%). M.p.: 224°-228° C.

Herkunft & Nachweise