Nitration

Nitration is a a general sulfuric acid.

Aromatic nitration

In "aromatic nitration," C.

(1) 2H₂SO₄ + HNO₃ → 2HSO₄^1- + NO₂⁺ + H₃O⁺

(2) C₆H₆ + NO₂⁺ → C₆H₅NO₂ + H⁺

(3) H⁺ + H₃O⁺ + 2HSO₄^1- → H₂O + 2H₂SO₄

The catalyst. It also absorbs water.

The formation of a nitronium ion (the electrophile) from sulfuric acid is shown below:

Scope

Selectivity is always a challenge in nitrations, The nitration of fluorenone is selective and yields a tri-nitro compound^[3] or tetra-nitro compound ^[4] by modifying reaction conditions. Another example of trinitration can be found in the synthesis of phloroglucinol.

Other nitration reagents include nitronium tetrafluoroborate, a nitronium salt. This compound can be prepared from boron trifluoride.^[5]

The substituents on aromatic rings affect the ethers resulting in para and ortho isomers.

The direct nitration of acetic anhydride followed by the actual nitration. Because the amide is a regular activating group the products formed are the para and ortho isomers. Heating the reaction mixture is sufficient to hydrolyze the nitroamide back to the nitroamine.

In the benzene reacts with nitric acid and mercury nitrate to give picric acid.

References