Synthesis and Nucleophilic Reactions of Cyano Substituted N‐Methoxyisoquinolinium Salts

Abstract

Starting from isoquinoline, the cyano substituted N‐methoxyisoquinolinium salts 1.1 and 1.4 are prepared. Their behaviour in the presence of O‐, C‐ and N‐nucleophiles in different aprotic solvents is examined: from the 1‐cyano substituted isoquinolinium derivative 1.1, 1‐ and 3‐animals or 1‐iminium salts are obtained depending on the amine used, and N‐methoxyisocarbostyril 4.1.1 in H2O and OH−. The reaction of the 4‐cyano‐N‐methoxyisoquinolinium salt 1.4 with amines yields 1‐aminals and with OH− the corresponding hemiaminal. Conversion with CN− results in dinitrile derivatives and N‐oxides.