A New Process for Producing Hydroxy Compounds of the Aromatic Series.
Year: 1898

page_text: [Communicated from abroad by THE FARBENFABRIKEN vormals FRIEDRICII
BAYER & Co., of Elberfeld, Germany.]
A New Process for Producing Hydroxy Compounds of the Aromatic
Series.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6, Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:-
It is known that hydroquinonediacetate is obtained when acetic anhydride is
allowed to act on benzoquinone, with or without the presence of sodium acetate
(see Buschka, "Berichte der Deutschen Chemischen Gesellschaft," vol. 14, p. 1327,
and Sarauw, "Annalen der Chemie," vol. 209, p. 127-129).
My foreign correspondents have now found that a totally different result is
obtained when quinones are treated with acetic anhydride in the presence of
concentrated sulphuric acid. In this case, triacetates of hydroxyhydroquinones are
formed in considerable quantities, which, when treated with suitable saponifying
agents, can easily be transformed into the free hydroxyhydroquinones.
In order to illustrate the new process, the following examples are given.
1
EXAMPLE A.
15 kilos., by weight, of benzoquinone are slowly stirred into a mixture pre-
pared from 45 kilos., by weight, of acetic anhydride, and about one litre of con-
centrated sulphuric acid. care being taken that the temperature does not rise
above 50 degrees Centigrade. By means of this operation, the quinone is dissolved.
the triacetate of hydroxyhydroquinone being formed according to the following
equation:-

page_text: as a brownish mass. When recrystallised from methylic alcohol, the new body
is obtained in the shape of pure white glittering leaves, which melt at 135 degrees
Centigrade.
If this substance is treated with suitable saponifying agents, the known alpha,-
beta, alpha, trioxynaphtalene is produced.
The same result is obtained if, instead of betanaphtochinone, alphanaphto-
quinone is used in the preceding example.
It may be remarked that the new process proceeds in an analogous manner on
using other quinones, such as toluquinone, or the like, in place of the quinones
employed in the examples.
My foreign correspondents wish it to be understood that they do not intend to
confine themselves to the particulars given in the examples, as these are merely
typical, and can be varied within wide limits, without altering the nature of the
present invention.
Dated this 9th day of May 1898
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
A New Process for Producing Hydroxy Compounds of the Aromatic
Series.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6, Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
It is known that hydroquinone-diacetate is obtained when acetic anhydride is
allowed to act on benzoquinone, with or without the presence of sodium acetate
(see Buschka, Berichte der Deutschen Chemischen Gesellschaft," vol. 14, p. 1327,
and Sarauw, "Annalen der Chemie," vol. 209, pp. 127-129).
My foreign correspondents have now found that a totally different result is
obtained when quinones are treated with acetic anhydride in the presence of
acid dehydrating agents, such as concentrated sulphuric acid, phosphoric acid,
or phosphoric anhydride. In this case, triacetates of hydroxyhydroquinones are
formed in considerable quantities, which, when treated with suitable saponifying
agents, can easily be transformed into the free hydroxyhydroquinones.
In order to illustrate the new process, the following examples are given:-
EXAMPLE A.
15 kilos. by weight of benzoquinone are slowly stirred into a mixture pre-
pared from 45 kilos. by weight of acetic anhydride, and about one litre of con-
centrated sulphuric acid, care being taken that the temperature does not rise
above 50 degrees Centigrade. By means of this operation the quinone is dissolved,
the triacetate of hydroxyhydro-quinone being formed according to the following
-
CH, – CO.
C,H,O, + 2
OCOCH
O=CH COOH + CHOCOCH,

page_text: new compound is separated in the shape of an oil, which soon becomes a
crystalline mass. When purified by recrystallisation from alcohol, this body
melts at from. 965 to 97 degrees Centigrade. It boils above 300°, nevertheless
it can be distilled without being decomposed.
If this triacetate is saponified, for instance, by means of hydrochloric acid,
the known hydroxyhydroquinone (melting at 1405 degrees Centigrade) is obtained
in a free state.
EXAMPLE B.
25 kilos. by weight of betanaphthoquinone are heated with 75 kilos. by weight
of acetic anhydride and 2 litres of concentrated sulphuric acid, at from 40 to 50
degrees Centigrade, until the reaction is finished. Subsequently the mixture is
poured into water, by means of which operation the new triacetate is separated
as a brownish mass. When recrystallised from methylic alcohol, the new body
is obtained in the shape of pure white glittering leaves, which melt at 135 degrees
Centigrade.
Of this substance is treated with suitable saponifying agents, the known alpha,
beta, alpha, trioxynaphtalene is produced.
The same result is obtained if, instead of betanaphthoquinone, alphanaphtho-
quinone is used.
It may be remarked that the new process proceeds in an analogous manner on
using other quinones, such as toluquinone or the like, in place of the quinones
employed in the examples.
My foreign correspondents wish it to be understood that they do not intend to
confine themselves to the particulars given in the examples, as these are merely
typical, and can be varied within wide limits, without altering the nature of the
present invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me from
abroad, I declare that what I claim is:-
1. The process for producing triacetyl derivatives of hydroxyhydroquinones,
which process consists in treating quinones with acetic anhydride in the presence
of acid dehydrating agents, such as concentrated sulphuric acid, phosphoric acid,
or phosphoric anhydride, substantially as herein before described.
2. The transformation of the triacetyl derivatives obtainable according to the
foregoing Claim 1, into the free hydroxyhydroquinones, by treating the said
triacetyl compounds with saponifying agents, substantially as hereinbefore
described.
3. As new articles of manufacture, the new bodies obtainable according to the
new processes herein before described and claimed.