Isoindole

Isoindole in heterocyclic chemistry is a benzo fused pyrrole. The compound is an isomer of indole and its reduced form is an isoindoline.

In solution the non-aromatic tautomer is predominant:


 * [[Image:Isoindoletautomerism.png|400px|Isoindole tautomerism]]

and therefore the compound resembles a pyrrole more than a simple imine. Isoindoles are building blocks for phthalocyanines which are relevant as dyes

Isoindole-1,3-diones
The commercially important phthalimide is an isoindole-1,3-dione with two carbonyl groups attached to the heterocyclic ring. Thalidomide is an infamous drug based on this framework.