The scope and limitations of aromatic diazines undergoing nucleophilic substitution reactions occurring via a radical-chain Sʀɴ1 mechanism were investigated. The study was conducted on a series of mono- and dihalogenated aromatic diazines interacting with various ketone enolates in ammonia. Results indicate that this previously unrecognized reaction pathway in these nitrogen heterocycles is easily obtained and should prove of great synthetic utility in preparation of substituted diazines. / Ph. D.