4-Aminobenzoic Acid → 4-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl)benzoic acid

Participants

Reaction Steps

41.1 g (0.3 mol) of p-aminobenzoic acid and 300 M of acetic acid were put into a 250 M flask to dissolve the p-aminobenzoic acid in the acetic acid, and then 29.4 g (0.3 mol) of maleic anhydride was slowly added thereto at 10° C. to obtain a yellow precipitate. This precipitate was recrystallized with a solution of DMF (dimethylformamide) and ethanol (50:50, w/w) to form an intermediate. The intermediate was treated at 85° C. for 15 minutes using sodium acetate and acetic anhydride, was cooled to room temperature, and was then precipitated in an ice water bath to obtain a precipitate. The obtained precipitate was recrystallized with a solution of ethyl acetate and n-hexane (50:50, w/w) to obtain N-(p-carboxyphenyl)maleimide.

Provenance & Evidence