o-aminobenzoic acid, 2-aminobenzoic acid, vitamin L1, Anthranilate
|Molar mass||137.14 g·mol−1|
|Appearance||white or yellow solid|
|Melting point||146 to 148 °C (295 to 298 °F; 419 to 421 K)|
|Boiling point||200 °C (392 °F; 473 K) (sublimes)|
|0.572 g/100 mL (25 °C)|
|Solubility||very soluble in chloroform, pyridine
soluble in ethanol, ether, ethyl ether
slightly soluble in trifluoroacetic acid, benzene
|Vapor pressure||0.1 Pa (52.6 °C)|
Refractive index (nD)
|1.578 (144 °C)|
Std enthalpy of
|Flash point||> 150 °C (302 °F; 423 K)|
|> 530 °C (986 °F; 803 K)|
LD50 (Median lethal dose)
|1400 mg/kg (oral, rat)|
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
Anthranilic acid (or o-amino-benzoic acid) is an aromatic acid with the formula C6H4(NH2)(CO2H). The molecule consists of a substituted benzene ring, hence is classed as aromatic, with two adjacent, or "ortho-" functional groups, a carboxylic acid and an amine. The compound is consequently amphoteric. In appearance, anthranilic acid is a white solid when pure, although commercial samples may appear yellow. It is sometimes referred to as vitamin L1 and has a sweetish taste. The anion [C6H4(NH2)(CO2)]−, obtained by the deprotonation of anthranilic acid, is called anthranilate.
Many routes to anthranilic acid have been described. Industrially it is produced from phthalic anhydride, beginning with amination:
- C6H4(CO)2O + NH3 + NaOH → C6H4(C(O)NH2)CO2Na + H2O
- C6H4(C(O)NH2)CO2Na + HOCl → C6H4NH2CO2H + NaCl + CO2
A related method involves treating phthalimide with sodium hypobromite in aqueous sodium hydroxide, followed by neutralization. In the era when indigo dye was obtained from plants, it was degraded to give anthranilic acid.
Industrially, anthranilic acid is an intermediate in the production of azo dyes and saccharin. It and its esters are used in preparing perfumes to imitate jasmine and orange, pharmaceuticals (loop diuretics e.g. furosemide) and UV-absorber as well as corrosion inhibitors for metals and mold inhibitors in soya sauce.
- Mentions of Anthranilic acid in news about organismic death process, example: http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001613
- The Merck Index, 10th Ed. (1983), p.62., Rahway: Merck & Co.
- C. J. Brown "The Crystal Structure of Anthranilic Acid" Proc. Royal Society of London A, 1968, vol. 302, pp. 185-199. doi:10.1098/rspa.1968.0003
- Takao Maki, Kazuo Takeda "Benzoic Acid and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a03_555.
- Vogel's Textbook of Practical Organic Chemistry, 4th Ed., (B. S. Furniss et al., Eds.) (1978), p.666, London: Longman.
- Logullo, F. M.; Seitz, A. H.; Friedman, L. (1973). "Benzenediazonium-2-carboxy- and Biphenylene". Org. Synth.; Coll. Vol. 5, p. 54
- Angelos SA, Meyers JA. The isolation and identification of precursors and reaction products in the clandestine manufacture of methaqualone and mecloqualone. Journal of Forensic Sciences 1985 Oct;30(4):1022-47. PMID 3840834