Phthalimide

:, a phthalimide, is a commercial fungicide.|left Phthalimide is used as a precursor to anthranilic acid, a precursor to azo dyes and saccharin. Alkyl halides can be converted to the N-alkylphthalimide: : C6H4(CO)2NH + RX + NaOH → C6H4(CO)2NR + NaX + H2O The amine is commonly liberated using hydrazine: : C6H4(CO)2NR + N2H4 → C6H4(CO)2N2H2 + RNH2 Dimethylamine can also be used. Some examples of phthalimide drugs include thalidomide, amphotalide, taltrimide, talmetoprim, and apremilast. With a trichloromethylthio substituent, a phthalimide-derived fungicide is Folpet. == Reactivity ==

It forms salts upon treatment with bases such as sodium hydroxide. The high acidity of the imido N-H is the result of the pair of flanking electrophilic carbonyl groups. 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, such as glycine. == Preparation ==

Phthalimide can be prepared by heating phthalic anhydride with alcoholic ammonia giving 95–97% yield. Alternatively, it may be prepared by treating the anhydride with ammonium carbonate or urea. It can also be produced by ammoxidation of o-xylene. : Phthalimide can also be prepared from phthalic acid by the following process: : Carboxylic acids when reacted with ammonia give ammonium salts, which in turn give amides when strongly heated. == Natural occurrence ==

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

Phthalimide has low acute toxicity with (rat, oral) of greater than 5,000 mg/kg. == References ==