Synthesis of 3-substituted isoindolin-1-ones by regioselective cyclization of nitrile with a styryl double bond

An efficient preparation of 3-substituted isoindolin-1-one was established via basic condensation of aromatic or aliphatic aldehyde with 6-alkoxy-3-methylbenzene-1,2,4-tricarbonitrile (1) in a one-pot reaction. The key step involved regioselective either hydrolysis or nucleophilic attack of the hydroxide anion to the 2-cyano group followed by 5-exo-trig cyclization with the involvement of the styryl double bond. The structure of isoindolinone and regiochemistry of the cyclization products were proved by spectroscopic methods.