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IUPAC name 5-Methyl-1,3-benzenediol
Other names 3,5-Dihydroxytoluene
CAS number 504-15-4
SMILES Cc1cc(O)cc(O)c1
Molecular formula C7H8O2
Molar mass 124.14 g/mol
Melting point

110.0-110.5 °C

Boiling point

289.5 °C

Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Orcin, or 3,5-dihydroxytoluene, C6H3(CH3)(OH)2, is an organic compound found in many lichens including Rocella tinctoria and Lecanora, and formed by fusing extract of aloes with potash.

It may be synthesized from toluene; more interesting is its production when acetone dicarboxylic ester is condensed with the aid of sodium. It crystallizes in colorless prisms with one molecule of water, which redden on exposure to air. Ferric chloride gives a bluish-violet coloration with the aqueous solution. Unlike resorcinol it does not give a fluorescein with phthalic anhydride. Oxidation of the ammoniacal solution gives orcein, C28H24N2O7, the chief constituent of the natural dye archil. Homo-pyrocatechin is an isomer (CH1: OH: OH= 1 3 :4), found as its methyl ether (creosol) in beech-wood tar.

See also


  • This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Orcin". A list of authors is available in Wikipedia.
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