A-Level Reactions of alkanes, alkenes and arenes: worked solution

Question

In Reaction II, benzaldehyde (C6H5CHO) is transformed into nitrobenzaldehyde. Give the reagents and the conditions needed to bring about Reaction II. Reagents: Conditions:

Reaction II converts benzaldehyde (C6H5CHO) into nitrobenzaldehyde, i.e. a nitro group (-NO2) is introduced onto the benzene ring. This is electrophilic substitution - nitration - in which the electrophile is the nitronium ion NO2+. The nitronium ion is generated by reacting concentrated nitric acid with concentrated sulfuric acid (H2SO4 acts as catalyst, protonating HNO3 to give NO2+ and water). The reaction is carried out with the temperature controlled (kept low, about 25-30 C) so that only mono-substitution occurs and further nitration/oxidation is avoided. (The -CHO group is a deactivating, meta-directing substituent, so the product is 3-nitrobenzaldehyde.)