Cyanochlorination and cyanation of isoquinolines

Abstract

Treatment of isoquinoline with sulphuryl chloride and potassium cyanide gave, in one preparative step, 4-chloro-1-cyanoisoquinoline and 1-carbamoyl-3-cyanoisoquinoline in yields dependent upon the proportions of reagents. 4-Chloroisoquinoline, 1,3-dicyanoisoquinoline, 3-cyanoisoquinoline, and 1-cyanoisoquinoline were also produced under different reaction conditions. The formation of the various products is explained in terms of successive electrophilic and nucleophilic attack by the reagents on the hetero-ring of isoquinoline followed by elimination reactions to regenerate an aromatic system. Cyanochlorination and cyanation of several isoquinoline derivatives and of quinoline were briefly studied.