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.

How do you make potassium phthalimide?

It can be prepared by adding a hot solution of phthalimide in ethanol to a solution of potassium hydroxide in ethanol; the desired product precipitates. This compound is a commercially available reagent used in the Gabriel synthesis of amines.

How is phthalimide obtained from anthranilic acid?

A related method involves treating phthalimide with sodium hypobromite in aqueous sodium hydroxide, followed by neutralization. In the era when indigo dye was obtained from plants, it was degraded to give anthranilic acid. Anthranilic acid was first obtained by base-induced degradation of indigo.