Abstract: Norcantharidinimide, 7-oxabicyclo [2, 2, 1] heptane-2,3-dicarboximide and its deaydroderivative, 7-oxabicyclo [2,2,l]-hept-5-ene-2, 3-dicarboxi-mide, were found to readily undergo Mannich reaction with primary or secondary amine to form N-Mannich bases in good yields. Thirty-five N-Mannich bases of this type were prepared from both aliphatic and aromatic amines.