Base‐Promoted Multicomponent Reaction of Phthalaldehyde With Amines and Sulfur: Access to 3‐Iminoisoindoline‐1‐Thiones

A base‐catalyzed, oxidative multicomponent condensation involving primary anilines, elemental sulfur, and phthalaldehyde is reported. Utilizing readily available starting materials, this protocol affords a novel series of structurally diverse 3‐iminoisoindoline‐1‐thiones in satisfactory yields under mild reaction conditions. Furthermore, the methodology was successfully extended to 1,8‐diaminonaphthalene, yielding the photosensitizer 12 H ‐isoindolo[2,1‐ a ]perimidine‐12‐thione in excellent yields with a simplified purification process via filtration.