p-Nitrobenzoic acid
[CAS# 62-23-7]

Identification

• Classification: Chemical reagent >> Organic reagent >> Aromatic acid
• Name: p-Nitrobenzoic acid
• Synonyms: 4-Nitrobenzoic acid
• Molecular Formula: C₇H₅NO₄
• Molecular Weight: 167.12
• CAS Registry Number: 62-23-7
• EC Number: 200-526-2
• SMILES: C1=CC(=CC=C1C(=O)O)[N+](=O)[O-]

Properties

• Density: 1.61
• Melting point: 239-242 °C
• Water solubility: <0.1 g/100 mL at 26 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H319-H332-H335
• Safety Statements: P261-P264-P264+P265-P270-P271-P280-P301+P317-P304+P340-P305+P351+P338-P317-P319-P330-P337+P317-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H332
Specific target organ toxicity - single exposure	STOT SE	3	H335
Reproductive toxicity	Repr.	2	H361
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H312
Carcinogenicity	Carc.	2	H351
Germ cell mutagenicity	Muta.	2	H341
Eye irritation	Eye Irrit.	2A	H319
Serious eye damage	Eye Dam.	1	H318

Discovery and Applications

p-Nitrobenzoic acid, also known as 4-nitrobenzoic acid, is an organic compound with the formula C7H5NO4. It was first synthesized in the 19th century during explorations of nitroaromatic compounds and their derivatives. Chemists discovered p-nitrobenzoic acid by nitrating benzoic acid, a straightforward process involving the introduction of a nitro group (–NO2) to the para position of the benzene ring relative to the carboxyl group (–COOH).

p-Nitrobenzoic acid is a valuable intermediate in organic synthesis. It is used to prepare various derivatives through reactions such as reduction, nitration, and esterification. The nitro group can be reduced to an amino group, producing p-aminobenzoic acid, which is a precursor for the synthesis of dyes, pharmaceuticals, and other organic compounds.

In pharmaceuticals, p-nitrobenzoic acid serves as an intermediate in the synthesis of drugs and active pharmaceutical ingredients (APIs). It is used to produce sulfa drugs, which are antibiotics effective against bacterial infections. The compound's derivatives are also utilized in the synthesis of antifungal and anti-inflammatory agents. The nitro and carboxyl groups provide versatile sites for chemical modification, enabling the development of various therapeutic compounds.

p-Nitrobenzoic acid is used in the manufacture of dyes and pigments. Its derivatives, particularly those formed by reduction to amines, are key components in the production of azo dyes.

In the polymer industry, p-nitrobenzoic acid is used to produce polyesters and other high-performance polymers. It acts as a monomer or a building block in the synthesis of polymers with specific properties, such as enhanced thermal stability and mechanical strength.

p-Nitrobenzoic acid is also employed in analytical chemistry as a standard or reference material. Its well-defined chemical properties make it suitable for calibrating instruments and validating analytical methods. It is often used in chromatography and spectroscopy to ensure accurate and reliable measurements.

In academic and industrial research, p-nitrobenzoic acid is used to study reaction mechanisms and develop new synthetic methodologies. Its well-understood reactivity and functional groups make it an ideal model compound for investigating chemical transformations and optimizing reaction conditions.

References

2004. Biosynthetic Origin of the Rare Nitroaryl Moiety of the Polyketide Antibiotic Aureothin: Involvement of an Unprecedented N-Oxygenase. Journal of the American Chemical Society, 126(12).
DOI: 10.1021/ja039328t

1997. Biotransformation and biodegradation of N-substituted aromatics in methanogenic granular sludge. FEMS Microbiology Reviews, 20(3-4).
DOI: 10.1016/s0168-6445(97)00031-4

2010. Use of p-nitrobenzoic acid in 7H10 agar for identification of Mycobacterium tuberculosis complex: a field study. The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 14(12).
URL: https://pubmed.ncbi.nlm.nih.gov/21144253