Probing the Reactivity of o‐Phthalaldehydic Acid/Methyl Ester: Synthesis of N‐Isoindolinones and 3‐Arylaminophthalides.

A new method for the synthesis of N-substituted isoindolinones and 3-arylaminophthalides was developed through aza-Wittig/cyclisation. The reaction of o-phthalaldehydic acid methyl ester with benzylic, aromatic and aliphatic azides gave N-isoindolinones whereas reaction of o-phthalaldehydic acid with the aromatic azides gave 3-arylaminophthalides.