N,N -Dialkyl aromatic amines react rapidly with nitrous acid to competitively produce a nitrosamine and a nitro compound. The mechanism of nitro compound formation involves a reaction of an amine radical cation with NO 2, while the nitrosamine is produced by two competing pathways, one of which involves N -α-CH deprotonation of a radical cation with subsequent oxidative generation of an imminium ion, and the other of which occurs through NOH elimination of a nitrosammonium ion (R 3 N − N O + ). All three pathways are linked through the reversible homolysis of R 3 N − N O + to NO and a radical cation.