A white crystalline nitrogenous substance, C2H4.(CO)2.NH, obtained by treating succinic anhydride with ammonia gas. It is a typical imido acid, and forms a series of salts. See Imido acid, under Imido.

Succinimide is a cyclic imide with the formula C4H5NO2. It appears as a white or colorless crystalline solid, and has a faint odor of sweat. It is used in a variety of organic synthesis, as well as in some industrial silver plating processes.