Polycyclic N-Hetero Compounds. V. A Novel Synthesis of Isoquinoline by the Vilsmeier Reaction of Phenylacetonitriles

Abstract

A novel synthesis of 3-chloro-or 3-chloro-4-formylisoquinolines by the Vilsmeier reaction of phenylacetonitriles is described. 3, 5-Dimethoxyphenylacetonitrile (I) afforded 3-chloro-6, 8-dimethoxyisoquinoline (II) in a good yield and a small amount of 3-chloro-6, 8-dimethoxy-4-formyl isoquinoline (III). Other phenylacetonitriles (V) afforded 3-chloro-4-formylisoquinoline derivatives (VI) only. The mechanism of this reaction is proposed.