Ring opening and ring contraction in reactions of some aminobromo‐ and dibromoisoquinolines with potassium amide in liquid ammonia

Abstract
Reactions of some aminobromo‐ and dibromoisoquinolines with KNH2 in liquid NH3 have been investigated. Compounds with an amino group and a bromo atom in positions α to the heteroatom, show a very fast ring opening, leading to o‐cyanobenzyl cyanide. The 1,4‐substituted aminobromoisoquinolines do not react; 4‐amino‐3‐bromoisoquinoline undergoes ring opening into o‐cyanobenzyl isocyanide, 3‐amino‐4‐bromoisoquinoline ring contraction to 1‐cyanoisoindole. The dibromoisoquinolines react primarily by nucleophilic substitution.