A Publication
of Reliable Methods
for the Preparation
of Organic Compounds
Annual Volume
Org. Synth. 1962, 42, 66
DOI: 10.15227/orgsyn.042.0066
Submitted by A. J. Fatiadi and W. F. Sager1.
Checked by B. C. McKusick and J. K. Williams.
1. Procedure
One hundred grams (0.44 mole) of stannous chloride dihydrate is added to a boiling solution of 10 g. (0.058 mole) of tetrahydroxyquinone2 in 200 ml. of 2.4N hydrochloric acid contained in a 1.5-l. beaker. The initial deep-red color disappears, and grayish crystals of hexahydroxybenzene precipitate. Two hundred fifty milliliters of 12N hydrochloric acid is added, and the mixture is heated to boiling with constant stirring. The beaker is removed from the hot plate, an additional 600 ml. of 12N hydrochloric acid is added, and the solution is cooled in a refrigerator. The hexahydroxybenzene is collected on a Büchner funnel fitted with a sintered-glass disk (Note 1) and sucked dry.
The crude hexahydroxybenzene is dissolved in 450 ml. of hot 2.4N hydrochloric acid containing 3 g. of hydrated stannous chloride and 1 g. of decolorizing carbon. The solution is filtered while hot, and the carbon is rinsed with 75 ml. of boiling water that is combined with the filtrate. One liter of 12N hydrochloric acid is added, and the mixture is cooled in a refrigerator. The snow-white crystals of hexahydroxybenzene that separate are collected under carbon dioxide or nitrogen (Note 2) on a Büchner funnel fitted with a sintered-glass disk. The hexahydroxybenzene is washed with 100 ml. of a cold 1:1 mixture of ethanol and 12N hydrochloric acid and dried in a vacuum desiccator over sodium hydroxide pellets; yield 7.1–7.8 g. (70–77%). It fails to melt on a hot plate at 310° (Note 3).
2. Notes
1. Filter paper cannot be used because it is attacked by strong hydrochloric acid.
2. By rapid manipulation it is possible to obtain a product of fair quality. The moist product is susceptible to air oxidation, as is shown by a development of pink coloration on the crystals. The filtration is best carried out under a blanket of carbon dioxide or nitrogen obtained by inverting a funnel attached to a source of carbon dioxide or nitrogen over the Büchner funnel.
3. The decomposition point of hexahydroxybenzene is not a good criterion of purity. If the product is light in color, there can be no significant amount of oxidized material in it, for even traces of tetrahydroxyquinone cause intense coloration. Decomposition of a sample with nitric acid followed by evaporation and ignition of the residue should give a negligible amount of tin oxide. The product can be characterized as the hexaacetate, m.p. 202–203°, by treating it with acetic anhydride and sodium acetate.3
3. Discussion
The present procedure is a modification of the procedure of Anderson and Wallis.4 Hexahydroxybenzene can also be prepared by acidic hydrolysis of potassium carbonyl3 or by nitration and oxidation of diacetyl hydroquinone.5
4. Merits of the Procedure
This is the most convenient synthesis of hexahydroxybenzene, and the present procedure gives better yields than reported by Anderson and Wallis.4 Hexahydroxybenzene is of interest as the most highly hydroxylated member of the polyhydroxybenzene family.
It has been used as a source of the biologically important myo-inositol6,7 (1235/46 isomer) by hydrogenation over palladium and of cis-inositol (123456 isomer) by hydrogenation over palladium-on-carbon.
This preparation is referenced from:

References and Notes
  1. Department of Chemistry, The George Washington University, Washington, D C.
  2. A. J. Fatiadi and W. F. Sager, this volume, p. 1011.
  3. B. Nietzki and T. Benckiser, Ber., 18, 1834 (1885).
  4. R. C. Anderson and E. S. Wallis, J. Am. Chem. Soc., 70, 2931 (1948).
  5. B. Nietzki and T. Benckiser, Ber., 18, 500, 1842 (1885).
  6. H. Wieland and R. S. Wishart, Ber., 47, 2082 (1914).
  7. S. J. Angyal and D. J. McHugh, Chem. & Ind. (London), 947 (1955).

Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

ethanol (64-17-5)

hydrochloric acid (7647-01-0)

acetic anhydride (108-24-7)

sodium acetate (127-09-3)

sodium hydroxide pellets (1310-73-2)

nitric acid (7697-37-2)

nitrogen (7727-37-9)

stannous chloride

carbon dioxide (124-38-9)

decolorizing carbon,
carbon (7782-42-5)

palladium (7440-05-3)

stannous chloride dihydrate (10025-69-1)

Benzenehexol (608-80-0)

Tetrahydroxyquinone (319-89-1)

tin oxide

potassium carbonyl

diacetyl hydroquinone

myo-inositol (87-89-8)