Obtained from pyrogallol-1,3-dimethyl ether-2-acetate upon oxidation with potassium dichromate: Hofmann, Ber. 11, 337 (1878); or by heating with nitric acid in alc soln: Graebe, Hess, Ann. 340, 237 (1905); by treating pyrogallol trimethyl ether with nitric acid: Will, Ber. 21, 608 (1888); from syringa acid: Graebe, Martz, ibid. 221; from sinapic acid: Gadamer, Ber. 30, 2333 (1897); from antiarole by oxidation with ferric chloride: Baker, J. Chem. Soc. 1928, 1029.