Abstract: 9,10-Dihydroanthracene-9,10-endo-α,β-succinimide has been prepared by fusing 9,10-dihydroanthracene-9,10-endo-α,β-succinic anhydride with urea. The condensation between this compound and formaldehyde forms the N-methylol derivative. The N-methylol derivative condenses easily with various amines to yield N-Mannich bases of 9,10-dihydroanthracene-9,10-endo-α,β-succinimide. Eighteen such bases were prepared(Table 2). These results lend support to Zinner and Herbig's proposal that in Mannich reaction of this type, the NH-acid component condenses first with formaldehyde to yield the N-methylol derivative, which is then converted to the desired N-Mannich base by the reaction with the amino-component.