Tasteless Salts of Ichthyolsulfonic Acid and similar Acids and Process of Making the same.
Year: 1898

page_text: Date of Application, 1st Mar., 1898
Complete Specification Left, 1st Dec., 1898-Accepted, 1st Mar., 1899
PROVISIONAL SPECIFICATION.
Tasteless Salts of Ichthyolsulfonic Acid and similar Acids and Process
of Making the same.
I, Dr. LUDWIG OTTO HELMERS, of 21, Bohnenstrasse, Hamburg, in the Empire
of Germany, Chemist, do hereby declare the nature of this invention to be as
follows:-
66
The ammonium, sodium and lithium compounds of the product obtained by the
action of sulphuric acid upon Seefeld mineral oil and known under the name of
ichthyol," heretofore employed in therapeutics, represent substances soluble
in water and having a very intense and peculiar taste. If the sulphonic-acid of
the ichthyol, serving as the initial product of these compounds be neutralized with
lime (calcium carbonate,) magnesia (magnesium carbonate) or a metallic oxide
(its carbonate salt) instead of employing ammonia, soda or lithium carbonate, then
the corresponding ichthyol-compounds of the alkaline earths, or of the metals,
respectively, are obtained. These compounds are entirely insoluble in water and
therefore may also be obtained by alternate decomposition of solutions of ichthyol-
alkalies with soluble salts of the alkaline earths or of the metals. After the dying
at a temperature of 100 degrees Centigrade, these ichthyol-salts admit of their
being pulverized and then form a brown black non-hygroscopic powder, which is
insoluble in water as well as in solutions of organic acids; on the other hand, it
readily dissolves in chloroform. When heated with mineral acids, the base again
splits off and ichthyol sulphonic-acid is re-formed. Also by heating with caustic
alkalies or carbonic alkalies the salts become decomposed: the ichthyol-alkaline
salt which is dissolved, and the oxide or carbonate respectively, of the base of the
ichthyol salt employed are formed.
In spite of their being insoluble in water, these ichthyol compounds yet possess
rather a strong taste, even after having been most carefully washed with water.
Experiments have shown that the taste is due to the existence of peculiar sub-
stances, of which a small quantity remains with the salts properly speaking.
In order to remove these substances a great many methods have been employed.
As already mentioned, the method of washing the product with water does not,
however, lead to the desired result. It is true that on boiling the product for
some considerable time with water, small quantities of substances of an extremely
bitter taste pass out of the insoluble salts into the aqueous solution, but the
residue does not thereby lose any of its taste. On the contrary it has been found,
that by a continued heating with water a decomposition takes place and that the
substances of bitter taste, absorbed by the water, are products split from the
ichthyol.
It was then attempted to remove the substances, producing the bitter taste, by
employing other extracting agents. Whereas alcohol has the effect of separating
the soluble ichthyol salts into the ichthyol sulphonic acid-salts proper, which are
soluble in alcohol, and into the sulphone like compounds, which are insoluble in
water and alcohol (see British Patent No. 6044 1893), the ichthyol salts, that is

page_text: to say, ichthyol-calcium magnesium and so forth, which are insoluble in water,
dissolve with difficulty even in alcohol. On the other hand, however, those sub-
stances which cause the bitter taste, very readily dissolve in alcohol, and it is owing
to this fact, that, by properly extracting the dried alkaline-earthy and metal salts
with alcohol these compounds can be obtained in an entirely tasteless state; other
solvents such as methyl alcohol, ether and acetic ether behave in a similar manner
like alcohol.
Upon further examining the substances, extracted by alcohol, it was found that,
when heated up to a temperature of about 130 to 140 degrees Centigrade, these
substances undergo a decomposition while tasteless products are formed. The
alcoholic extract originally presenting a light brown colour in this chemical action
turns perceptibly darker and melts down to a hard and brittle mass under disen-
gagement of vapours.
In consequence of these facts attempts were made, to destroy those substances
admixed to the ichthyol salts even to the soluble ichthyol salts and causing the
peculiar taste, without using extracting agents by simply heating the products,
with the object, thus to obtain tasteless salts.
In the case of the salts, soluble in water namely the ichthyol-sodium, ichthyol-
ammonium, ichthyol-lithium, the experiment did not prove the supposition to be
correct. The substances heated for ten hours to a temperature of about 130 to
140 degrees Centigrade, were still possessing a distinct taste; this taste, therefore, is
peculiar to the alkali salts. Moreover, these salts, and especially the ichthyol-
ammonium, when being heated suffer decomposition in a considerable measure,
which becomes already apparent by the incomplete solubility of the heated product
in water.
The ichthyol salts of the earthy alkalies and metals behave differently to the
alkaline salts. On exposing these products for about 6 hours up to a tempera-
ture of about 130 to 140 degrees Centigrade, they lose their taste entirely while
otherwise remaining unchanged, thus for example, the heated products are split
up just as completely, though with somewhat more difficulty, by mineral acids
and alkalies.
Like the ichthyol salts also behave the corresponding salts of sulphonic-acid
compounds derived from sulphureted hydro-carbons combined with sulphuric acid.
Dated this 1st day of March 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Tasteless Salts of Ichthyolsulfonic Acid and similar Acids and Process
of Making the same.
I, Dr. LUDWIG OTTO HELMERS, of 21, Bohnenstrasse, Hamburg, in the Empire
of Germany, Chemist, 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:―
"
The ammonium, sodium and lithium compounds of the product obtained by the
action of sulphuric acid upon Seefeld mineral oil and known under the name of
ichthyol," heretofore employed in therapeutics, represent substances soluble
in water and having a very intense and peculiar taste. If the sulphonic-acid of
the ichthyol, serving as the initial product of these compounds be neutralized with
lime (calcium carbonate), magnesia (magnesium carbonate) or a metallic oxide or

page_text: carbonate of a metal instead of employing ammonia, soda or lithium carbonate, then
the corresponding ichthyol-compounds of the alkaline earths, or of the metals,
respectively, are obtained. These compounds are entirely insoluble in water and
therefore may also be obtained by alternate decomposition of solutions of ichthyol-
alkalies with soluble salts of the alkaline earths or of the metals. After drying
at a temperature of 100 degrees Centigrade, these ichthyol-salts admit of
being pulverized and then form a brown black non-hygroscopic powder, which is
insoluble in water as well as in solutions of organic acids: on the other hand, it
readily dissolves in chloroform. When heated with mineral acids, the base again
splits off and ichthyol sulphonic-acid is re-formed. Also by heating with caustic
alkalies or carbonic alkalies the salts become decomposed: the ichthyol-alkaline
salt which is dissolved, and the oxide or carbonate respectively, of the base of the
ichthyol salt employed are formed.
In spite of their being insoluble in water, these ichthyol compounds yet possess
rather a strong taste, even after having been most carefully washed with water.
Experiments have shown that the taste is due to the existence of peculiar sub-
stances, of which a small quantity remains mixed with the salts properly speaking.
In order to remove these substances a great many methods have been employed.
As already mentioned, the method of washing the product with water does not,
however, lead to the desired result. It is true that on boiling the product for
some considerable time with water, small quantities of substances of an extremely
bitter taste pass out of the insoluble salts into the aqueous solution, but the
residue does not thereby lose any of its taste. On the contrary it has been found,
that by a continued heating with water a decomposition takes place and that the
substances of bitter taste, absorbed by the water, are products split from the
ichthyol.
It was then attempted to remove the substances, producing the bitter taste, by
employing other extracting agents. Whereas alcohol has the effect of separating
the soluble ichthyol salts into the ichthyol-sulphonic acid-salts proper, which are
soluble in alcohol, and into the sulphone like compounds, which are insoluble in
water and alcohol (see British Patent No. 6044 1893), the ichyol salts, that is
to say, ichthyol-calcium magnesium and so forth, which are insoluble in water,
dissolve with difficulty even in alcohol. On the other hand, however, those sub-
stances which cause the bitter taste, very readily dissolve in alcohol, and it is owing
to this fact, that, by properly extracting the dried alkaline-earthy and metallic salts
with alcohol these compounds can be obtained in an entirely tasteless state; other
solvents such as methyl alcohol, ether and acetic ether behave in a similar manner
like alcohol.
Upon further examining the substances, extracted by alcohol, it was found that,
when heated up to a temperature of about 130 to 140 degrees Centigrade, theso
substances undergo a decomposition while tasteless products are formed. The
alcoholic extract originally presenting a light brown colour in this chemical action
turns perceptibly darker and melts down to a hard and brittle mass under disen-
gagement of vapours.
In consequence of these facts attempts were made, to destroy those substances
mixed with the ichthyol salts-even to the soluble ichthyol salts and causing the
peculiar taste, without using extracting agents by simply heating the products,
in order to obtain tasteless salts.
In the case of the salts, soluble in water namely the ichthyol-sodium, ichthyol-
ammonium, ichthyol-lithium, the experiment did not prove the supposition to be
correct. The substances heated for ten hours to a temperature of about 130 to
140 degrees Centigrade, still possessed a distinct taste; this taste therefore, is
peculiar to the alkali salts. Moreover, these salts, and especially the ichthyol-
ammonium, when being heated, suffer decomposition in a considerable measure,
which becomes already apparent by the incomplete solubility of the heated product
in water.
The ichthyol salts of the earthy alkalies and metals behave differently from the

page_text: alkaline salts. On exposing these products for about 6 hours up to a tempera-
ture of about 130 to 140 degrees Centigrade, they lose their taste entirely while
otherwise remaining unchanged; thus, for example, the heated products are split
up just as completely, though with somewhat more difficulty, by mineral acids
and alkalies.
Like the ichthyol salts also behave the corresponding salts of sulphonic-acid
compounds derived from sulphuretted hydro-carbons combined with sulphuric acid.
The following examples may serve for illustrating the process:-
(a) One kilogramme of ichthyol sulphonic-acid, such as obtained by the action
of concentrated sulphuric acid or its substitutes upon Seefeld mineral oil dissolved
in about 10 litres of water, and the solution while being stirred is gradually
neutralized by means of chalk. Carbonic acid is set free during this operation
and ichthyol calcium is formed, which deposits upon the bottom of the vessel,
the water standing above the deposit, is decanted after some time has lapsed. In
order to separate the ichthyol-calcium from the calcium sulphate and excess of
calcium carbonate, the said ichthyol-calcium is dissolved in chloroform and the
chloroform subsequently filtered and removed by distillation. The residue is then
reduced to powder and extracted in a suitable apparatus by means of alcohol. By
the action of the alcohol the substances, causing the peculiar taste, are dissolved,
whilst the ichthyol-calcium, about one quarter of a kilogramme in weight, remains
undissolved in the form of a tasteless powder.
(b) One kilogramme of ichthyol sulphonic acid, which, by repeated dissolution
in water and precipitation by means of hydrochloric acid, is freed from the
sulphuric acid adherent thereto, is dissolved in five kilogrammes of water and
neutralized by means of ammonia. The solution is subsequently mixed with about
ono and a half litres of a calcium-chloride solution of 20 per cent., the precipi-
tated ichthyol calcium is washed with water so long as hydrochloric acid is present
in the water, and the admixed water is finally evaporated at the lowest possible
temperature. The dry residue, which amounts to about one half kilogramme,
lastly, is for 5 to 8 hours exposed to a temperature up to about 130 to 140 degrees
Centigrade, at the end of which operation it has lost 3 to 4 per cent. of its weight.
(c) One kilogramme of ichthyol-ammonium, as brought into the market dissolved
in 20 litres of water is mixed, while stirring, with three litres of a magnesium-
chloride solution of ten per cent. and the mixture then left untouched for twelve
hours. After this period has elapsed, a compact precipitate of ichthyol magnesium
has been separated upon the bottom of the vessel. The liquid, standing above
this precipitate, is decanted, the latter washed repeatedly with water, then dried
at a temperature of 100 degrees Centigrade, powdered and extracted by means of
ether. The residue forms a tasteless powder consisting of ichthyol-magnesium.
(d) One kilogramme of ichthyol ammonium dissolved in 12 litres of water is,
while stirring the product, mixed with one half kilogramme of ferric sulphate
dissolved in fifteen litres of water and having a little acetic acid added to it. The
liquid becomes clear after the lapse of a few hours and is then decanted from the
precipitate, which consists of ichthyol iron, by washing the ichthyol iron, with
water, it is freed from the iron solution adherent in excess; it is subsequently
dried at a temperature of 100 degrees. Finally the temperature is raised to about
120 degrees Centigrade for several hours.
Having now particularly described and ascertained the nature of my said inven
tion and in what manner the same is to be performed I declare that what I
claim is:
-
1. The process of rendering tasteless sulphonic acid salts of earthy metals and
metals proper derived from sulphuretted hydrocarbons combined with sulphuric
acid by extracting the salts with alcohol or other solvents having the effect of
discolving those substances which cause the taste, or by heating the salts up to
about 180 to 140 degrees Centigrade substantially as set forth.
2. As a new product of manufacture the herein described neutral salts, consist-

page_text: ing of an alkaline earthy and metallic base and a sulphonic acid compound derived
from sulphuretted hydrocarbons combined with sulphuric acid, which salts are of a
pulverulent form, insoluble in water and devoid of taste and smell.
Dated this 1st day of December 1898
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.