Abstract: The present invention provides a process for recovering a metal nitrite, e.g., sodium nitrite, from a reaction mixture formed from an aromatic displacement reaction such as the synthesis of an aromatic bis(ether phthalimide) in an organic non-polar solvent. The process comprises forming a reaction mixture from the synthesis of an aromatic bis(ether phthalimide) comprising a recoverable amount of metal nitrite; treating the reaction mixture with an amount of water effective to produce an aqueous solution phase of metal nitrite and an organic non-polar phase; and separating the aqueous solution phase of metal nitrite from the organic non-polar phase.