3,5-Dinitrobenzoic acid

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3,5-Dinitrobenzoic acid
Skeletal formula
Skeletal formula
Ball-and-stick model
Ball-and-stick model
Names
Preferred IUPAC name
3,5-Dinitrobenzoic acid
Identifiers
3D model (JSmol)
1914286
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.002.501 Edit this at Wikidata
EC Number
  • 202-751-1
UNII
  • InChI=1S/C7H4N2O6/c10-7(11)4-1-5(8(12)13)3-6(2-4)9(14)15/h1-3H,(H,10,11) checkY
    Key: VYWYYJYRVSBHJQ-UHFFFAOYSA-N checkY
  • 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
  • O=[N+]([O-])c1cc(cc([N+]([O-])=O)c1)C(=O)O
Properties
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)[2]
Vapor pressure 0.000001 mmHg[1]
Acidity (pKa) 2.82
Hazards
GHS labelling:[2]
GHS07: Exclamation mark
Warning
H302, H315, H319, H335, H413
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)
[1]
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
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 checkY☒N ?)

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

[edit]

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

[edit]

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

Uses

[edit]

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))[6]

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

[edit]

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

[edit]
  1. ^ a b "3,5-dinitrobenzoic acid SDS". thermofisher.com. ThermoFisher Scientific. 25 March 2024. Retrieved 23 October 2025.
  2. ^ a b Sigma-Aldrich Co., 3,5-dinitrobenzoic acid.
  3. ^ a b 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. ^ a b "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.