Preparation of Nitro Compounds Preparation and Properties
From Hydrocarbon :
Aromatic Nitro Compounds :
→ The mixture of conc. HNO3 + conc. H2SO4 is known as nitrating mixture.
Step – I :
Step – II :
Step – III :
H3O+ + HSO4– → H2O + H2SO4
→ From Aliphatic Nitro Compounds : Alkane in vapour phase reacts with fuming HNO3 at 673 K temperature gives a mixture of different nitro alkanes.
From Alkyl Halides :
→ Alkyl bromide or alkyl iodide reacts with AgNO2 with a1coho forms nitroalkane.
→ This method is not used for preparation of aromatic nitro compound because aromatic compounds are less reactive for nucleophilic substitution.
→ Silver Nitrite (AgNO2) is a covalent compound hence lone pair of electron present on nitrogen is available for attack. Therefore nitroalkanes are formed as main product.
→ From Aniline : By diazotization of aniline by nitrous acid (NaNO2 + HCl) a salt is obtained which then react with aqueous sodium nitrite mixed with copper powder to form nitrobenzene.