3-Nitrobenzoic acid is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with the formula C₆H₄(NO₂)CO₂H. It is an aromatic compound and under standard conditions, it is an off-white solid. The two substituents are in a meta position with respect to each other, giving the alternative name of ''m''-nitrobenzoic acid. This compound can be useful as it is a precursor to

3-aminobenzoic acid 3-Aminobenzoic acid (also known as ''meta''-aminobenzoic acid or MABA) is an organic compound with the molecular formula H2NC6H4CO2H. MABA is a white solid, although commercial samples are often colored. It is only slightly soluble in water. It i ...

, which is used to prepare some dyes..

Preparation

It is prepared by

nitration In organic chemistry, nitration is a general class of chemical processes for the introduction of a nitro group into an organic compound. The term also is applied incorrectly to the different process of forming nitrate esters between alcohols an ...

benzoic acid Benzoic acid is a white (or colorless) solid organic compound with the formula , whose structure consists of a benzene ring () with a carboxyl () substituent. It is the simplest aromatic carboxylic acid. The name is derived from gum benzoin, ...

at low temperatures. Both

2-Nitrobenzoic acid 2-Nitrobenzoic acid or ''o''-nitrobenzoic acid is an organic compound with the formula C6H4(NO2)CO2H. It is prepared by oxidation of 2-nitrotoluene with nitric acid.Takao Maki, Kazuo Takeda "Benzoic Acid and Derivatives" in Ullmann's Encycloped ...

and 4-Nitrobenzoic acid are produced as side products, with yields of approximately 20% and 1.5% respectively. Since carboxylic acid functional groups are

electron withdrawing In chemistry, an electron-withdrawing group (EWG) is a substituent that has some of the following kinetic and thermodynamic implications: *with regards to electron transfer, electron-withdrawing groups enhance the oxidizing power tendency of the ...

, during an

electrophilic aromatic substitution Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic n ...

reaction of nitration, substituents are directed to a meta position which explains this regiochemistry. A less efficient route involves nitration of

methyl benzoate Methyl benzoate is an organic compound. It is an ester with the chemical formula C6H5CO2CH3. It is a colorless liquid that is poorly soluble in water, but miscible with organic solvents. Methyl benzoate has a pleasant smell, strongly reminisce ...

, followed by hydrolysis. Alternatively, oxidative C-C bond cleavage of 3-nitroacetophenone to the corresponding aryl carboxylic acid, has been demonstrated. A further synthesis involves the oxidation of 3-nitrobenzaldehyde.

Properties

With a p''K''_a of 3.47, 3-nitrobenzoic acid is about ten times more acidic than

. The conjugate base of benzoic acid is stabilised by the presence of the electron withdrawing nitro group which explains its increased acidity in comparison to unsubstituted benzoic acid. It is typically soluble in oxygenated and chlorinated solvents.

Reactivity

The presence of both carboxylic acid and

nitro Nitro may refer to: Chemistry *Nitrogen, a chemical element and a gas except at very low temperatures, with which many compounds are formed: **Nitro compound, an organic compound containing one or more nitro functional groups, -NO2 **Nitroalkene, ...

functional groups deactivate the ring with respect to

reactions.

Safety

The compound is likely of modest toxicity, with (i.v., mouse) of 640 mg/kg. This compound can cause skin and eye irritation with symptoms of exposure including methemoglobin, sensitisation, irritation, and corneal damage.

References

{{DEFAULTSORT:Nitrobenzoic acid, 3- Benzoic acids Nitrobenzenes