N-Nitroso-N-methylaniline is a nitrosylated N-methyl aniline that is described to form adducts with DNA. N-Nitroso-N-methylaniline is useful for studying enzymatic denitrosation processes. N-demethylation of N-Nitroso-N-methylaniline catalysed by cytochrome P450 is described to proceed through an electrophilic benzenediazonium ion which is demonstrated to form triazene DNA adducts at the N6-position of adenine residues.