Under which of the following reaction conditions, aniline gives p-nitro derivative as the major product?
• Direct nitration of aniline is not possible because it gives a mixture of ‘ortho’ and ‘para’ products.
• So acetic anhydride is used to produce acetanilide in order block the ‘ortho’ position activation of aniline and then it undergoes nitration and forms specifically
para-nitro aniline.
Both (i) Acetyl chloride/pyridine followed by reaction with conc. H2SO4 + conc. HNO3.
• (ii) Acetic anyhdride/pyridine followed by conc. H2SO4 + conc. HNO3 reagents can be used for the procedure.
But (iii) Dil. HCl followed by reaction with conc. H2SO4 + conc. HNO3.
(iv) Reaction with conc. HNO3 + conc. H2SO4 cannot produce acetanilide.