Manufacture of Sulphonic Acids of Guaiacol and of Creosote and of Metallic Salts of these Sulphonic Acids.
Year: 1897

page_text: Date of Application, 14th June, 1897
Complete Specification Left, 4th Feb., 1898-Accepted, 2nd Apr., 1898
PROVISIONAL SPECIFICATION.
Manufacture of Sulphonic Acids of Guaiacol and of Creosote and of
Metallic Salts of these Sulphonic Acids.
I, HAROLD IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by F. Hoffmann-La Roche & Co.,
of Basle, Switzerland, Manufacturing Chemists,) to be as follows:-
Tiemann and Koppe have already described (Berlin Berichte 14, 2019) the
action of concentrated sulphuric acid on guaiacol. Whilst, however, both of
these investigators observed that two guaiacol sulphonic acids or their salts are
obtained, of which the one cannot be separated in a solid form, my correspondents
have found that by using pure crystallised guaiacol and working between certain
temperature limits it is possible to obtain the one or the other of the two isomeric
sulphonic acids, the salts of which being of great purity, may be separated in the
solid form.
They have further found that by the action of strong sulphuric acid on creosote
two different creosote sulphonic acids are formed according to the temperature at
which the sulphonation is effected. These new creosote sulphonic acids have the
following advantages over the creosote heretofore used in therapeutics :-
1) They are nearly odourless and have only at first a bitter taste, afterwards
the taste is agreeable and sweetish.
2) They are neutral and have no injurious action on the mucous membrane.
3) They are extremely easily soluble in water.
A. MANUFACTURE OF THE ISOMERIC GUAIACOL SULPHONIC ACIDS AND THEIR SALTS.
EXAMPLE I.
Molecular proportions of fused pure guaiacol and concentrated sulphuric acid,
or one part of guaiacol and 1 to 3 parts of concentrated sulphuric acid are mixed,
being stirred the while, care being taken that the temperature does not rise above
70 to 80° C.
When the sulphonation is at an end the excess of sulphuric acid is separated
from the dark red coloured mixture by the method usual for phenol-sulphonic
acids, for example by diluting with water, precipitating with barium carbonate
filtering and washing the contents of the filter.
From the solution of barium guaiacol-sulphonate obtained in this way, the free
acid is isolated, in dilute aqueous solution, by adding dilute sulphuric acid.
The acid can only be obtained in this form; by evaporating the nearly colour-
less aqueous solution a thick strongly coloured syrup is left which can neither be
distilled without decomposition nor crystallised from the known solvents, water,
alcohol, ether and alcohol &c.
The metallic salts of this guaiacol sulphonic acid I can be prepared by saturating

page_text: effected by the method described under Example I, except that the action of
the sulphonic acid on the creosote is allowed to proceed at 150 to 160° C. The
aqueous solutions of the acid and its salts are somewhat more darkly coloured than
those of the creosote sulphonic acid I and its salts. With ferric chloride the salts
give, in aqueous solution, an intense bluish-green colour which is changed by
ammonia to a fine ruby or Bordeaux-red.
Manufacture of Sulphonic Acids of Guaiacol and of Creosote and of
Metallic Salts of these Sulphonic Acids.
I, HAROLD IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, in
the County of London, Chartered Patent Agent, do hereby declare the nature of
this invention (as communicated to me from abroad by F. Hoffmann-La Roche & Co.,
of Basle, Switzerland, Manufacturing Chemists) and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement;-
-
Tiemann and Koppe have already described (Berlin Berichte 14, 2019) the
action of concentrated sulphuric acid on guaiacol. Whilst, however, both of
these investigators observed that two guaiacol sulphonic acids or their salts are
obtained, of which the one cannot be separated in a solid form, my correspondents
have found that by using pure crystallised guaiacol and working between certain
temperature limits it is possible to obtain the one or the other of the two isomeric
sulphonic acids, the salts of which being of great purity, may be separated in the
solid form.
They have further found that by the action of strong sulphuric acid on creosote
two different creosote sulphonic acids are formed according to the temperature at
which the sulphonation is effected. These new creosote sulphonic acids have the
following advantages over the creosote heretofore used in therapeutics:
--
1) They are nearly odourless and have only at first a bitter taste, afterwards
the taste is agreeable and sweetish.
2) They are neutral and have no injurious action on the mucous membranes.
3) They are extremely easily soluble in water.
A. MANUFACTURE OF THE ISOMERIC GUAIACOL SULPHONIC ACIDS AND THEIR SALTS.
EXAMPLE I.
Molecular proportions of fused pure guaiacol and concentrated sulphuric acid,
or one part of guaiacol and 1 to 3 parts of concentrated sulphuric acid are mixed,
being stirred the while, care being taken that the temperature does not rise above
70 to 80° C.
When the sulphonation is at an end the excess of sulphuric acid is separated
from the dark red coloured mixture by the method usual for phenol-sulphonic
acids, for example by diluting with water, precipitating with barium carbonate
filtering and washing the contents of the filter.
From the solution of barium guaiacol-sulphonate obtained in this way, the free
acid is isolated, in dilute aqueous solution, by adding dilute sulphuric acid.

page_text: The acid can only be obtained in this form; by evaporating the nearly colour-
less aqueous solution a thick strongly coloured syrup is left which can neither be
distilled without decomposition nor crystallised from the known solvents, water,
alcohol, ether and alcohol, &c.
The metallic salts of this guaiacol sulphonic acid I can be prepared by saturating
the aqueous solution of the acid with the mono- or bi-carbonates of the metals
to be used, or by double decomposition of the barium guaiacol-sulphonate with the
sulphates of the metals to be used.
These salts, in dilute aqueous solution, give a violet-blue colouration with a
little ferric chloride, changing to bright yellow on addition of ammonia.
Guaiacol-sulphonic acid I can also be prepared by mixing solid, powdered or
fused guaiacol with the above prescribed proportion of concentrated sulphuric
acid in the cold and finishing the sulphonation, which has already occurred to
some extent, by heating at 70 to 80° C.
EXAMPLE II.
Molecular proportions of guaiacol and concentrated sulphuric acid, or one part
of guaiacol and from 1 to 3 parts of concentrated sulphuric acid, are mixed, and the
mixture is gradually heated to 150 to 160° C. whereby it acquires a very dark
colour contrary to the case given under Example I.
The separation of the free guaiacol-sulphonic acid II, which is also stable
only in aqueous solution, or of its salts is effected by the method described under
Example I.
The salts of this acid are distinguished from their isomerides by the facts that
they are extremely easily soluble in water but separate from concentrated solutions
in the form of crystals, and give, in dilute, aqueous solution, with ferric chloride,
an intense greenish-blue colouration, which changes to a brilliant Bordeaux-red
on addition of ammonia.
The salts of both the isomeric guaiacol-sulphonic acids are colourless and nearly
tasteless; they have no caustic action on the mucous membranes and may there-
fore be used in medicine, for which purpose they are more advantageous than free
guaiacol is, owing to the aforesaid properties.
Molecular proportions of creosote and concentrated sulphuric acid, or one part
of creosote and from 1 to 3 parts of concentrated sulphuric acid, are gradually mixed
being stirred the while, care being taken that the heat of the reaction shall not
raise the temperature above 55 to 60°.
After this sulphonation is over the mixture is poured into water and filtered
after a short time from the separated, greasy, disagreeably smelling portion. The
creosote-sulphonic acid is isolated from the sulphuric acid solution by the usual
method, for example by precipitating with barium carbonate, filtering, decomposing
the resulting barium creosote-sulphonate with dilute sulphuric acid, again filtering
and evaporating the aqueous solution. The free acid is stable only in aqueous
solution by strongly evaporating the nearly colourless solution becomes a thick
dark coloured syrup. The salts of this creosote-sulphonic acid I may be obtained
by saturating the aqueous solution of the acid with the mono- or bi-carbonates
of the metals to be used, or by double decomposition of the barium creosote-
sulphonate with metallic sulphates. The salts are best preserved in concentrated
aqueous solution; by evaporating such a solution and allowing it to stand for
some time a part of the salt sometimes crystallises; the mother liquid is then
poured off and the crystals are dried at a moderate temperature. The aqueous
solution of the salts give an intense violet-blue colouration with a little ferric
chloride, changing to bright yellow on addition of ammonia.

page_text: Creosote-sulphonic acid I can also be prepared by mixing creosote and con-
centrated sulphuric acid in the above prescribed proportions, in the cold and
completing the sulphonation, already begun, by heating at 55 to 60° C.
EXAMPLE II.
The preparation of the isomeric creosote-sulphonic acid II and its salts is
effected by the method described under Example I, except that the action of
the sulphuric acid on the creosote is allowed to proceed at 150 to 160° C. The
aqueous solutions of the acid and its salis are somewhat more darkly coloured than
those of the creosote sulphonic acid I and its salts. With ferric chloride the salts
give in aqueous solution an intense bluish-green colour which is changed by
ammonia to a fine ruby or Bordeaux-red.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. Process for the manufacture of sulphonic acids of guaiacol, consisting in
mixing solid or melted guaiacol with concentrated sulphuric acid in the cold and
then heating the mixture to from 70° to 80° C. or in sulphonating melted guaiacol
with concentrated sulphuric acid at a temperature of from 70° to 80° C. while
utilising the reaction temperature, substantially as described.
2. Process for the manufacture of sulphonic acids of guaiacol consisting in
mixing guaiacol and concentrated sulphuric acid and heating the same to from
150° to 160° C., substantially as described.
3. Process for the manufacture of sulphonic acids af creosote, consisting in
mixing together creosote and concentrated sulphuric acid in the cold, and com-
pleting the commenced reaction by afterwards heating to from 55° to 60° C.,
or by sulphonating creosote with concentrated sulphuric acid at a temperature of
from 550 to 60° C. while utilising the reaction temperature, substantially as
described.
4. Process for the manufacture of sulphonic acids of creosote consisting in
reacting upon creosote with concentrated sulphuric acid at a temperature of from
150° to 160° C., substantially as described.
5. The conversion of the sulphonic acids of guaiacol and of creosote into their
metallic salts substantially as described.
6. As new manufactures, the sulpho-acids of guaiacol and of creosote, as also of
the metallic salts thereof herein described.
Dated this 4th day of February 1898.
ABEL & IMRAY,
Agents for the Applicant.