If the CH 3 of the acetyl protecting group were labelled with 14C you would be able to detect 14C in the final sulfanilamide product. Complete the equation that depicts the equilibrium reaction between the anilinium ion and acetate ion. Show a reasonable mechanism for the formation of acetanilide from aniline and acetic anhydride. The protonation of the unshared pair of electrons on nitrogen of aniline is the first step of the acetylation mechanism. The acetic anhydride to be added later is only soluble in aqueous HCl.
Aniline is poorly soluble in water.
Aniline is a catalyst in the reaction. The acetic anhydride to be added later will react in a dangerously exothermic fashion if added to water only. Draw the structure of this by-product. In the acetylation of aniline, aniline is dissolved in dilute HCl as its hydrochloride salt. Acetic anhydride is then added and immediately afterward a solution of sodium acetate is added.