Central nervous system active compounds. XIII. The use of aminomethylene phthalides in the synthesis of phthalideisoquinoline alkaloids

Abstract

Dimethylaminomethyleneisobenzofuranones react with alkoxyphenylethylamines in aqueous acidic solution to give phthalide isoquinolines (tetrahydroisoquinolinylisobenzofuranones) in moderate yields. N-Methylation gives the naturally occurring phthalideisoquinoline alkaloids. A number of examples of this reaction sequence are reported, including the synthesis of (±)-cordrastine, (±)-corlumine and (±)-adlumine.