4-Nitrobenzoic acid

Chemical properties

light yellow crystalline powder

The Uses of 4-Nitrobenzoic acid

4-Nitrobenzoic Acid is used in the synthesis of anti-Trypanosoma cruzi agents in the treatment of chagas disease.

Definition

ChEBI: A nitrobenzoic acid having the nitro group at the 4-position.

Production Methods

p-Nitrobenzoic acid (4-Nitrobenzoic acid) is produced commercially by the oxidation of 4-nitrotoluene with molecular oxygen. Oxidation with 15 % nitric acid at 175 ℃ produces the acid in 88.5 % yield. An interesting method involves the nitration and subsequent oxidation of polystyrene. This method uses the steric hindrance of the polymer chain to improve the para to ortho ratio of the product.

Synthesis Reference(s)

Tetrahedron Letters, 26, p. 2387, 1985 DOI: 10.1016/S0040-4039(00)94834-2
Journal of the American Chemical Society, 72, p. 5012, 1950 DOI: 10.1021/ja01167a051

Air & Water Reactions

Insoluble in water.

Reactivity Profile

p-Nitrobenzoic acid is incompatible with strong oxidizers. p-Nitrobenzoic acid is also incompatible with strong bases (potassium hydroxide). p-Nitrobenzoic acid may react with cyanides.

Fire Hazard

p-Nitrobenzoic acid is combustible.

Toxicology

Among various nitroaromatics, 4-nitrobenzoic acid (4-NBA) is one of the simplest and basic derivates of the explosives. Moreover, 4-NBA harms human health and causes severe water and atmosphere pollution. 4-Nitrobenzoic acid is stable, toxic, and non-biodegradable. US/Zn0 was found to degrade more than 85% of 4-nitrobenzoic acid in 30 min. There was an apparent synergistic effect between ultrasound and Zn[1-2].

Toxicity

As 4-nitrobenzoic acid is a metabolite of 4-nitrotoluene, which also induces tumours of the clitoral gland as well as tumours in other organs, 4-nitrobenzoic acid is classified in analogy to 4-nitrotoluene in Carcinogen Category 3?B. 4-Nitrobenzoic acid has a weak mutagenic potency in vitro. It did not induce micronuclei in vivo or in vitro. There is no suitable data in humans to derive an MAK value. In rats, a 15-month and 2-year study resulted in a NOAEL of 60 mg/ kg body weight and day for delayed body weight gain in the females. Toxicokinetic scaling results in 147 mg/m3 concentration in workplace air. The LOAEC for local effects on the olfactory epithelium of rats in a 14-day study is 150 mg/m3, the NOAEC 20 mg/m3.

Purification Methods

Purify it as for 3-nitrobenzoic acid above. The amide has m 201.6o (from H2O). [Beilstein 9 III 1537, 9 IV 1072.]

References

[1] Shan Chong. “Ultrasound/Zn0 for aqueous 4-nitrobenzoic acid degradation.” Desalination and Water Treatment 322 1 (2016): 24990–24998.
[2] Xue-Huan Xin . “A luminescent barium-based metal-organic framework: Synthesis, structure and efficient detection of 4-nitrobenzoic acid.” Inorganic Chemistry Communications 97 (2018): Pages 129-133.