3,5-Dinitrobenzoic acid

3,5-Dinitrobenzoic acid

Skeletal formula Ball-and-stick model
Names
Preferred IUPAC name 3,5-Dinitrobenzoic acid
Identifiers
CAS Number	99-34-3  Y
3D model (JSmol)	Interactive image
Beilstein Reference	1914286
ChEBI	CHEBI:73914  Y
ChEMBL	ChEMBL118713  Y
ChemSpider	7155  Y
ECHA InfoCard	100.002.501
EC Number	202-751-1
PubChem CID	7433
UNII	4V3F9Q018P
CompTox Dashboard (EPA)	DTXSID7059195
InChI InChI=1S/C7H4N2O6/c10-7(11)4-1-5(8(12)13)3-6(2-4)9(14)15/h1-3H,(H,10,11) Y Key: VYWYYJYRVSBHJQ-UHFFFAOYSA-N Y InChI=1/C7H4N2O6/c10-7(11)4-1-5(8(12)13)3-6(2-4)9(14)15/h1-3H,(H,10,11) Key: VYWYYJYRVSBHJQ-UHFFFAOYAQ
SMILES O=[N+]([O-])c1cc(cc([N+]([O-])=O)c1)C(=O)O
Properties
Chemical formula	C7H4O6N2
Molar mass	212.117 g·mol−1
Appearance	Yellow or colourless crystals
Melting point	204 to 206 °C (399 to 403 °F; 477 to 479 K) [1]
Vapor pressure	0.000001 mmHg [2]
Acidity (pKa)	2.82
Hazards
GHS labelling: [1]
Pictograms
Signal word	Warning
Hazard statements	H302, H315, H319, H335, H413
Precautionary statements	P261, P264, P270, P271, P273, P280, P301+P312+P330, P302+P352, P304+P340+P312, P305+P351+P338, P332+P313, P337+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)	[2] 2 1 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

3,5-Dinitrobenzoic acid is an organic chemical that is an important corrosion inhibitor and is also used in photography.^{[ citation needed ]} This aromatic compound is used by chemists to identify alcohol components in esters and in the fluorometric analysis of creatinine.

Synthesis

3,5-dinitrobenzoic acid is obtained from benzoic acid by the nitration reaction with nitric acid in the presence of concentrated sulfuric acid. ^{[3] [4]}

The nitration can also be started with 3-nitrobenzoic acid, which leads to yields of approximately 98%. ^[5]

Properties

3,5-Dinitrobenzoic acid is an odorless, yellowish solid. Due to the mesomeric effect of the two nitro groups, it is more acidic (pK_a = 2.82) than benzoic acid (pK_a = 4.20) and 3-nitrobenzoic acid (pK_a = 3.47).^{[ citation needed ]}

Uses

3,5-Dinitrobenzoic acid finds use in the identification of various organic substances, especially alcohols, by derivatization. For such an analysis, the substance to be analyzed is reacted with 3,5-dinitrobenzoic acid in the presence of sulfuric acid in order to form a derivate. By doing so, many substances that are liquid or have a low melting point are converted to easily crystallized derivates with sharp melting points. For instance, alcohols can be identified by the melting point of their esters with 3,5-dinitrobenzoic acid. This method is also applicable to a large number of amines.

Identification of isopropanol as a derivate of 3,5-dinitrobenzoic acid:
3,5-dinitrobenzoic acid-2-propylester (mp.: 123 °C (253 °F))

Compared to 4-nitrobenzoic acid, another acid that is used similarly, derivates of 3,5-dinitrobenzoic acid have higher melting points, so that it is preferred when the 4-nitrobenzoic acid derivate has a melting point too low to be accurately identified. ^[6]

For more sensitive compounds, the reaction is carried out using the acid chloride, 3,5-dinitrobenzoyl chloride. This allows for example the identification of amino acids. ^[3]

Explosives

Various heavy metal salts (including barium, lead, and silver) of 3,5-dinitrobenzoic acid are known to be high explosives. The lead salts are (relatively) stable and were patented for use in priming compositions. ^[7]

References

1. Sigma-Aldrich Co., 3,5-dinitrobenzoic acid.
2. "3,5-dinitrobenzoic acid SDS". thermofisher.com. ThermoFisher Scientific. 25 March 2024. Retrieved 23 October 2025.
3. Saunders, B. C.; Stacey, G. J.; Wilding, I. G. E. (1942). "The Preparation of 3:5-Dinitrobenzoic Acid and 3:5-Dinitrobenzoyl Chloride – Observations on the Acylation of Amino-acids by means of 3:5-Dinitrobenzoyl Chloride and certain other Acid Chlorides". Biochem. J. 36 (3–4): 368–375. doi:10.1042/bj0360368. PMC   1265703 . PMID   16747534.
4. R. Q. Brewster; Bill Williams; Ross Phillips (1942). "3,5-Dinitrobenzoic Acid". Organic Syntheses . 22: 48. doi:10.15227/orgsyn.022.0048 .
5. Lebedev, B. A.; Dolmatov, V. Yu.; Zubarev, P. S.; Latynov, N. V.; Aleksandrov, M. M.; Ponamareva, R. I (1988). "Preparation of 3,5-dinitrobenzoic acid from meta-nitrobenzoic acid". Pharmaceutical Chemistry Journal. 22 (5): 399–401. doi:10.1007/BF00769656. S2CID   34335456..
6. "Table VI: Organic derviatives of alcohols". CRC handbook of tables for organic compound identification (3., 14. print ed.). Boca Raton, Fla: CRC Press. 1985 [1967]. p. 80. ISBN   0-8493-0303-6.
7. Fedoroff, Basil T.; Sheffield, Oliver E.; Clift, George D.; Reese, Earl F. (1 January 1962). Encyclopedia of Explosives and Related Items: Volume 2 - B (Explosif) through Chloric Acid (PDF). Dover, NJ: Army Armament Research Development And Engineering Center, Picatinny Arsenal - Warheads Energetics And Combat Support Armaments Center. p. B-72. PATR 2700. Retrieved 25 October 2025.