Phthalimide

Phthalimide is an imide, which is a chemical compound with two carbonyl groups bound to a primary amine or ammonia. It is a white solid at room temperature.

Preparation
Phthalimide can be prepared by heating phthalic anhydride with aqueous ammonia giving 95-97% yield. Alternatively, it may be prepared by fusing the anhydride with ammonium carbonate.

Uses
Phthalimide is used in plastics, in chemical synthesis, and in research.

Reactivity
It forms salts with various metals such as potassium and sodium due to its high acidity caused by the electrophilic carbonyl groups attached to the nitrogen atom, which can be made by reacting phthalimide with metal carbonates. Potassium phthalimide, made by reacting phthalimide with potassium carbonate in water at 100°C or with potassium hydroxide in absolute ethanol, is used in the Gabriel synthesis of primary amines, and the Gabriel synthesis of glycine has yields as high as 85%.

Natural occurrence
Kladnoite is a natural mineral analog of phthalimide. It is very rarely found among few burning coal fire sites.