Abstract
The mechanism of the conversion of chloropyrazine into 2‐cyanoimidazole by the action of potassium amide in liquid ammonia has been investigated. Using 2‐chloro[4′ 15N]pyrazine and 2‐chloro[2′ 14C]pyrazine it has been shown that ring contraction occurs by a nucleophilic attack of the amide ion at C(3), followed by fission of the C(3)‐N(4) bond.