Mono-nitration of aromatic compounds via their nitric acid salts

Aromatic compounds bearing a basic nitrogen atom can be converted to the corresponding nitric acid salts. Mono-nitration of the compounds can be carried out by adding a dichloromethane solution of the salts to sulfuric acid, or by adding acetyl chloride (or trifluoroacetic anhydride) to a dichloromethane solution of the salts. This protocol provides, among other benefits, the most convenient and reliable way for the prevention of over-/under-nitration and is especially suitable for scale-up.