Anthranilic acid

Anthranilic acid

Anthranilic acid
Skeletal formula of anthranilic acid
Ball-and-stick model of the anthranilic acid molecule
Names
IUPAC name
2-aminobenzoic acid
Other names
o-aminobenzoic acid, 2-aminobenzoic acid, vitamin L1, Anthranilate
Identifiers
 Y
ChEBI  Y
ChEMBL  Y
ChemSpider  Y
DrugBank  N
EC number 204-287-5
Jmol-3D images Image
Image
KEGG  Y
PubChem
RTECS number CB2450000
Properties
C7H7NO2
Molar mass 137.14 g·mol−1
Appearance white or yellow solid
Odor odorless
Density 1.412 g/cm3
Melting point 146 to 148 °C (295 to 298 °F; 419 to 421 K)[1]
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
log P 1.21
Vapor pressure 0.1 Pa (52.6 °C)
Acidity (pKa) 2.14
1.578 (144 °C)
Thermochemistry
-380.4 KJ/mol
Hazards
Safety data sheet External MSDS
R-phrases R36 R37
S-phrases S26 S39
NFPA 704
1
2
0
Flash point > 150 °C (302 °F; 423 K)
> 530 °C (986 °F; 803 K)
Lethal dose or concentration (LD, LC):
LD50 (Median dose)
1400 mg/kg (oral, rat)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 N  (: Y/N?)

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.[2] The anion [C6H4(NH2)(CO2)], obtained by the deprotonation of anthranilic acid, is called anthranilate.

Contents

  • Structure 1
  • Production 2
    • Biosynthesis 2.1
  • Uses 3
  • See also 4
  • External links 5
  • References 6

Structure

Although not usually referred to as such, it is an amino acid. Solid anthranilic acid consists of both the amino-carboxylic acid and the zwitterionic ammonium carboxylate forms.[3]

Production

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

The resulting sodium salt of phthalamic acid is decarbonylated via a Hofmann rearrangement of the amide group, induced by hypochlorite:[4]

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.[5] In the era when indigo dye was obtained from plants, it was degraded to give anthranilic acid.

Biosynthesis

anthranilate is the precursor to the amino acid tryptophan.

Anthranilic acid is biosynthesized from chorismic acid. It is the precursor to the amino acid tryptophan via the attachment of phosphoribosyl pyrophosphate to the amine group.

Uses

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.

Anthranilic acid can be used in benzyne.[6]

It is also a DEA List I Chemical because of its use in making the now-widely outlawed euphoric sedative drug methaqualone (Quaalude, Mandrax).[7]

It has been suggested that anthranilate esters could be efficient insect repellents, replacing DEET.

Fenamic acid is a derivative of anthranilic acid,[8]:235 which in turn is a nitrogen isostere of salicylic acid, which is the active metabolite of aspirin.[8]:235 Several non-steroidal anti-inflammatory drugs, including mefenamic acid, tolfenamic acid, flufenamic acid, and meclofenamic acid are derived from fenamic acid or anthranilic acid and are called "anthranilic acid derivatives" or "fenamates".[9]:17

See also

External links

  • C. elegansAnthranilate Fluorescence Marks a Calcium-Propagated Necrotic Wave That Promotes Organismal Death in mention of Anthranilic acid in news about organismic death process

References

  1. ^ IPCS
  2. ^ The Merck Index, 10th Ed. (1983), p.62., Rahway: Merck & Co.
  3. ^ 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
  4. ^ 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.
  5. ^ Vogel's Textbook of Practical Organic Chemistry, 4th Ed., (B. S. Furniss et al., Eds.) (1978), p.666, London: Longman.
  6. ^ Logullo, F. M.; Seitz, A. H.; Friedman, L. (1973). "Benzenediazonium-2-carboxy- and Biphenylene".  
  7. ^ 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
  8. ^ a b Sriram D, Yogeeswari P. Medicinal Chemistry, 2nd Edition. Pearson Education India, 2010. ISBN 9788131731444
  9. ^ Auburn University course material. Jack DeRuiter, Principles of Drug Action 2, Fall 2002 1: Non-Steroidal Antiinflammatory Drugs (NSAIDS)