# Which occurs first: nitration or oxidation of aniline by concentrated nitric acid?

Which of the cases is possible or both or none?

• Would definitely oxidise. Protect the amine but reacting with acyl chloride to make abide to make the aromatic ring less activated. – RobChem Dec 26 '16 at 15:21
• None, oxidative oligomerisation happens. – Mithoron Dec 26 '16 at 16:31

Concentrated $\ce{HNO3}$ is ‘only’ around $70~\%$. To add a nitro functionality by electrophilic aromatic substitution, typically the $\ce{NO2+}$ cation is required which is formed only by strong dehydrating agents such as sulfuric acid:
$$\ce{O2N-OH <<=>[\ce{H2SO4}][-\ce{HSO4-}] O2N-OH2+ ->[][-\ce{H2O}] O=\overset{+}{N}=O}\tag{1}$$