Nitrobenzoic acid explained

Nitrobenzoic acids are derivatives of benzoic acid. Two are commercially important. They are about ten times more acidic than the parent benzoic acid.^[1]

Nitrobenzoic acid can be prepared through the oxidation of styrene in boiling nitric acid.^[2]

The salts and esters of nitrobenzoic acids are known as nitrobenzoates.

Isomers

The three isomers of nitrobenzoic acid are:

• 2-Nitrobenzoic acid is prepared by oxidation of 2-nitrotoluene.
• 3-Nitrobenzoic acid is a precursor to 3-aminobenzoic acid, which in turn is used to prepare some dyes. It can be prepared by nitration of benzoic acid. It also can be prepared by treating benzaldehyde under nitration conditions, a process that initially converts the aldehyde to the acid.
• 4-Nitrobenzoic acid is a precursor to 4-aminobenzoic acid, which is in turn used to prepare the anesthetic procaine. 4-Nitrobenzoic acid is prepared by oxidation of 4-nitrotoluene.

References

1. Takao Maki, Kazuo Takeda "Benzoic Acid and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, Weinheim.
2. The Reactions of Monomeric Styrenes . Everson, William . Chemical Reviews . October 1949 . 45 . 2 . 183–345 . 10.1021/cr60141a001.