2079. Chloranilic Acid

Nomenclature

CAS number: 87-88-7
2,5-Dichloro-3,6-dihydroxy-2,5-cyclohexadiene-1,4-dione; 2,5-dichloro-3,6-dihydroxy-p-benzoquinone.
C6H2Cl2O4; mol wt 208.98.
C 34.48%, H 0.96%, Cl 33.93%, O 30.62%.

Description and references

Prepd from chloranil by alkaline hydrolysis: Conant, Fieser, J. Am. Chem. Soc. 46, 1866 (1924).

Chemical structure

Properties

Red crystals, mp 283-284°. Tendency to sublime. Relatively strong dibasic acid. Absorption max (pH 4 in water): 290-340 nm, 520-555 nm.

Use

Reacts with metal cations to form stable salts. Used in spectrophotometry: Hart, Org. Chem. Bull. 33, no. 3 (1961).