5783. Meconin

Nomenclature

CAS number: 569-31-3
6,7-Dimethoxy-1(3H)-isobenzofuranone; 6,7-dimethoxyphthalide; opianyl; meconinic acid lactone.
C10H10O4; mol wt 194.18.
C 61.85%, H 5.19%, O 32.96%.

Description and references

Isolated from opium by Dublanc in 1832. Occurs also in the root of Hydrastis canadensis L., Ranunculaceae: Freund, Ber. 22, 456, 459 (1889). Is formed in oxidation of noscapine with HNO3. Synthesis from o-veratric acid: Edwards et al., J. Chem. Soc. 1925, 195; Wilson et al., J. Org. Chem. 16, 792 (1951). From opianic acid: Brown, Newbold, J. Chem. Soc. 1952, 4878.

Chemical structure

Properties

White, optically inactive needles; sharp bitter taste. mp 102-103°. uv max: 213, 308 nm (ε 25000, 3800). Sol in 700 parts cold, 22 parts boiling water; sol in alcohol, benzene, chloroform, ether, glacial acetic acid; slowly sol in alkalies with formation of alkali salt of meconinic acid, (CH2OH)(CH3O)2C6H2COOH. The acid itself is unstable, rapidly changing to lactone.