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CHAPTER II

NITRATION THEORIES

THERE are two main theories concerning the nitration of hydrocarbons by means

of the nitrating agents described above.

The first theory assumes a two-stage reaction with an addition reaction as

the first stage and the second assumes that nitration is a double exchange re-

action. At present the second theory has more adherents, since it is based on more

recent experimental data.

NITRATION AS AN ADDITION REACTION

According to Michael [l], on nitrating aromatic hydrocarbons an intermediate

addition product is formed, which has one hydrocarbon hydrogen atom attached

to one oxygen atom of nitric acid, and a carbon atom of the aromatic ring directly

attached to the nitrogen atom of the acid. The “aldol” formed gives off water in the

presence of an excess of nitric or sulphuric acid. The mechanism was depicted

by the author as follows:

(1)

Likewise the mechanism of nitration of an aromatic hydrocarbon with nitro-

sulphuric acid was formulated by Michael as:

(2)

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