Synthesis of anthranilic acid

Preparation of anthranilic acid

Preparation of anthranilic acid

Preparation of anthranilic acid

5 g of N-(2-methylphenyl)acetamide, 10.3 g of crystallised magnesium sulphate, and 600 ml of water are heated to 75-80° C. At this temperature 14.6 g of solid potassium permanganate are added, and the whole heated to 85° C for 1.5 hours. The liquid is filtered hot, and the filtrate on cooling acidified with dilute sulphuric acid, when acetanthranilic acid (2-acetamidobenzoic acid) is precipitated. m.p. 185° C. The acetyl group can be split off by boiling with dilute caustic alkali, or better, with dilute hydrochloric acid. Anthranilic acid itself melts at 145° C.

Preparation of organic compounds, E. de. Barry Barnett, 53, 1912

Preparation of anthranilic acid

Preparation of anthranilic acid

40 g of finely powdered phthalimide and 80 g of sodium hydroxide are dissolved together in 280 ml of water, the solution being cooled during the operation. The solution is agitated, and 400 g of a 5% solution of sodium hypochlorite run in. When all is added, the solution is warmed for a few minutes at 80° C to complete the reaction; it is then cooled and neutralised exactly with hydrochloric acid (or sulphuric acid). An excess of strong acetic acid is added to precipitate the anthranilic acid, which is filtered off and washed with water. Any anthranilic acid remaining in the filtrate is precipitated as copper anthranilate by the addition of a saturated solution of copper(II) acetate. After standing for some time the precipitate is filtered off and suspended in a small quantity of warm water, while a current of hydrogen sulfide is passed into the suspension. The copper sulphide formed is filtered off, and anthranilic acid recovered from the filtrate by concentration on a water bath. It may be recrystallised from hot water. Total yield 85%, m.p. 145° C.

Systematic organic chemistry, by W. M. Cumming, 298-299, 1937.

Preparation of anthranilic acid

Preparation of anthranilic acid

Alternatively, 40 g of sodium hydroxide are dissolved in 200 ml of water and to this solution 32 g of bromine are added under cooling. The obtained NaBrO is cooled to -10°  C and with proper stirring a mixture of 29.6 g phthalimide and 20 mL of cold water are introduced. After the addition of phthalimide  the reaction mixture is warmed to 10° C, the solution becomes completely transparent. Then 24 g of finely divided sodium hydroxide are added, the temperature reaches 40 ° C and the reaction mixture is heated to 80° C. Then the cooled reaction mixture is treated with 64 ml of conc. hydrochloric acid and 30 ml of glacial acetic acid and left to stand overnight. The precipitated anthranilic acid is filtered, washed with a small amount of ice water and crystallized from boiling water in the presence of active carbon.

Л.М. Кульберг, Синтезы органических реактивов для неорганического анализа, 16, (1947) (LM Koulberg, Synthesis of organic reagents for inorganic analysis, 16, (1947))


2-aminobenzoic acid



InChI Key


Canonical SMILES


MeSH Synonyms

2-aminobenzoic acid, anthranilate, anthranilic acid, anthranilic acid, cadmium salt, anthranilic acid, calcium (2:1) salt, anthranilic acid, dihydrochloride, anthranilic acid, hydrochloride, anthranilic acid, monolithium salt, anthranilic acid, monosodium salt

Depositor-Supplied Synonyms

anthranilic acid, 2-aminobenzoic acid, o-aminobenzoic acid, anthranilate, o-Anthranilic acid, o-Carboxyaniline, 2-Carboxyaniline, vitamin L1, Benzoic acid, 2-amino-, 118-92-3, 1-Amino-2-carboxybenzene, ortho-Aminobenzoic acid, Carboxyaniline, 2-amino-Benzoic acid, Vitamin L, Kyselina anthranilova, Kyselina o-aminobenzoova, Benzoic acid, o-amino-, NCI-C01730, Anthranate, Caswell No. 033G, Anthranic acid, o-Anthranilate, o-amino-Benzoate, 2-amino-Benzoate, 6-AMINOBENZOIC ACID, amino benzoic acid, Ortho-amidobenzoate, Ortho-aminobenzoate, anthranilic acid gr, Kyselina anthranilova [Czech], 2-Aminophenylacetate, o-Aminobenzoate, o-amino-Benzoic acid, 2-amino benzoic acid, Benzoic acid, amino-, Kyselina o-aminobenzoova [Czech], Ortho-amidobenzoic acid, NSC 144, H-2-Abz-OH, CCRIS 49, BRN 0471803, UNII-0YS975XI6W, AI3-02408, CHEBI:30754, HSDB 1321, RWZYAGGXGHYGMB-UHFFFAOYSA-N, EINECS 204-287-5, SBB007560, NCGC00091175-01, DSSTox_CID_94, Cupric anthranilate, NSC 3937, DSSTox_RID_75363, DSSTox_GSID_20094, Bis(anthranilato)copper, BE2, Bis(o-aminobenzoato)copper, Copper, bis(anthranilato)-, Anthranilic acid-(ring-13C6), Calcium anthranilate (1:2), Copper, bis(2-aminobenzoato)-, NSC3937, 1321-11-5, 80206-34-4, CAS-118-92-3, o-Aminobenzoic acid copper complex, Copper, bis(2-aminobenzoato-N,O)-, Antranilic Acid, 2-aminobenzoicacid, amino-benzoic acid, o-Aminobenzoesaeure, vitamin L1

Removed Synonyms

2-aminobenzoate, AMINOBENZOIC ACID, Isatoic anhydride, 2-Aminophenylacetic acid, WLN: ZR DVQ, C7H7NO2, anthranilic acid, cadmium salt, Anthranilic acid, hydrochloride, 2-AA, CID227, anthranilic acid, dihydrochloride, anthranilic acid, monosodium salt, anthranilic acid, monolithium salt, anthranilic acid, calcium (2:1) salt, 4-27-00-07875 (Beilstein Handbook Reference), C031385, SOA

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