Org. Synth. 1948, 28, 68
DOI: 10.15227/orgsyn.028.0068
HYDROQUINONE DIACETATE
[Hydroquinone, diacetate]
Submitted by W. W. Prichard
Checked by Homer Adkins and Maynette Vernsten.
1. Procedure
One drop of concentrated sulfuric acid is added to a mixture of 110 g. (1.0 mole) of hydroquinone and 206 g. (190.3 ml., 2.02 moles) of acetic anhydride (Note 1) in a 1-l. Erlenmeyer flask. The mixture is stirred gently by hand; it warms up very rapidly, and the hydroquinone dissolves. After 5 minutes the clear solution is poured onto about 800 ml. of crushed ice. The white crystalline solid which separates is collected on a Büchner filter and washed with 1 l. of water. The filter cake is pressed occasionally to facilitate the removal of water; the solid is dried to constant weight over phosphorus pentoxide in a vacuum desiccator. The nearly pure product weighs 186–190 g. (96–98%) and melts at 121–122° (Note 2); it can be recrystallized from dilute ethanol (Note 3).
2. Notes
1.
The use of commercial
acetic anhydride in this preparation sometimes results in appreciably lower yields. The checkers used the freshly redistilled reagent.
2.
The melting point is recorded in the literature
1,2 as
121° and as
123–124°.
3.
Recrystallization from
50% ethanol (by weight) permits a
93–94% recovery of material melting at
121.5–122.5°; about 365 g. (400 ml.) of the solvent is required for 100 g. of the crude product.
3. Discussion
Hydroquinone diacetate has been prepared by the treatment of
hydroquinone with
acetic anhydride, both in the presence
1,3,4 and in the absence
5,6,7 of strong acid catalysts, by the treatment of the
sodium salt of hydroquinone with
acetic anhydride, and by the reaction of
hydroquinone with
acetic anhydride in the presence of
sodium acetate.
8,9 It has also been prepared from
hydroquinone and
acetyl chloride;
10 the acetylation with
acetyl chloride is reported to be improved by the addition of
metallic magnesium.
11
This preparation is referenced from:
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
ethanol (64-17-5)
sulfuric acid (7664-93-9)
acetic anhydride (108-24-7)
sodium acetate (127-09-3)
acetyl chloride (75-36-5)
hydroquinone (123-31-9)
magnesium (7439-95-4)
Hydroquinone diacetate,
Hydroquinone, diacetate (1205-91-0)
phosphorus pentoxide (1314-56-3)
sodium salt of hydroquinone
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