JEE Main · 2019 · 12 Jan 2019 · Shift 1 · Compounds Containing Nitrogen

Reaction with an alkyl halide is an $N$-alkylation, so it runs faster when the nitrogen lone pair is more available to act as a nucleophile. In the imide the nitrogen lone pair is tied up by delocalisation into two flanking carbonyl groups, leaving it the least reactive. In the amide only one carbonyl pulls on the lone pair, so it is somewhat more available. The ring-substituted aniline bearing an electron-withdrawing group has its lone pair drawn in less than an amide's but still somewhat withdrawn, while the simple arylamine, whose lone pair is only partly delocalised into the ring, is the most nucleophilic and reacts fastest. The increasing order of reactivity is the imide, then the amide, then the cyano-substituted amine, then the simple amine.