Question

Нитрование метилбензола в присутствии концентрированной серной кислоты приводит к образованию...

Answer 1

2,4,6-тринитротолуола 

Answer 2

Nitration of methylbenzene in the presence of concentrated sulfuric acid

The nitration of methylbenzene in the presence of concentrated sulfuric acid leads to the formation of 1-nitro-2-methylbenzene.

Concentrated sulfuric acid is used as the solvent in this nitration reaction. Sulfuric acid acts as both a catalyst and a protonating agent. It protonates the methylbenzene, making it more electrophilic and susceptible to electrophilic aromatic substitution by the nitronium ion (NO2+).

The nitronium ion preferentially attacks the position ortho to the methyl substituent due to its deactivating effect. This gives 1-nitro-2-methylbenzene as the major product. Minor amounts of the 1,3- and 1,4- isomers may also form.

The methyl group deactivates the benzene ring by inducing a negative charge on the ortho and para positions through resonance. This makes these positions less reactive towards electrophilic substitution. Therefore, the meta position sees the least amount of deactivation and is attacked to give the 1-nitro isomer.

So in summary, nitration of methylbenzene using concentrated sulfuric acid yields 1-nitro-2-methylbenzene as the major product due to the deactivating effect and steric hindrance posed by the methyl substituent.