117. Aconitic Acid

Nomenclature

CAS number: 499-12-7
1-Propene-1,2,3-tricarboxylic acid; equisetic acid; citridic acid; achilleic acid.
C6H6O6; mol wt 174.11.
C 41.39%, H 3.47%, O 55.14%.

Description and references

Found in leaves and tubers of Aconitum napellus L., Ranunculaceae, in various species of Achillea (Compositae) and Equisetum (Equisetaceae), in beet root, and in sugar cane. Can be prepd commercially from calcium magnesium aconitate recovered from sugar cane juice: McCalip, Seibert, Ind. Eng. Chem. 33, 637 (1941); from molasses: Regna, Bruins, ibid. 48, 1268 (1956). Most of the commercial aconitic acid is, however, manufactured by sulfuric acid dehydration of citric acid: Bruce, Org. Synth. coll. vol. II, p 12 (1943); by using methanesulfonic acid instead of sulfuric: Cranston, US 2727066 (1955 to Daniel F. Kelly). Aconitic acid prepd by any of the above methods has the trans-configuration which is the form described here.

Chemical structure

Properties

Leaflets, plates from water. Decompn 198-199° (capillary inserted in oil bath at 190°); decompn 204-205° (capillary in oil bath at 195°); decompn 209° (electrically heated bar). K1 at 25° = 1.58 × 103; K2 = 3.5 × 105. One gram dissolves in 5.5 ml water at 13°, in 2 ml water at 25°. Soluble in 2 parts of 88% alcohol at 12°. Slightly sol in ether.

Derivative

Triethyl ester.

Properties

bp5 155°.

Derivative

Tributyl ester.

Properties

bp3 190°.

Use

Manuf itaconic acid. As plasticizer for buna rubber and plastics. Used in form of triethyl or tributyl ester.