3-Chloroimino-3H-dibenzo[f,ij]isoquinoline-2,7-dione, with CAS number 32943-25-2, is a heterocyclic organic compound. It is structurally characterized as a chlorinated isoindoline-1,3-dione derivative, specifically a chlorinated phthalimide analogue. This compound is a solid at room temperature. This chemical serves primarily as a versatile synthetic building block and reagent in organic chemistry. Its core structure, featuring a reactive chloroimino group adjacent to a cyclic imide, makes it a valuable precursor for the synthesis of more complex heterocyclic systems and functionalized isoindoline derivatives. It is utilized in research-scale synthesis for constructing pharmacologically relevant scaffolds. As a specialized reagent, it is not a commodity chemical and is typically used in academic and industrial research laboratories. Standard safety precautions for handling organic compounds, including the use of personal protective equipment and adequate ventilation, should be observed due to the potential hazards associated with its reactive functional groups.