Year: 1887

page_text: Date of Application, 28th May, 1887
Complete Left, 28th Feb., 1888
Complete Accepted, 6th Apr., 1888
YY e, ADOLF LIEBMANN, D.D.
Street, Manchester in the County of Lancaster, Consulting Chemists, do hereby
declare the nature of this invention to be as follows:-
This process consists as follows:-
One part, by weight, of alpha-naphtol is mixed with four parts, by weight, of
concentrated sulphuric acid and then heated for about one hour at 130° C.
The resulting mixture of sulpho-acids is converted into their corresponding barium
salts. This mixture of barium salts is then suspended in about 10 parts of water,
and gaseous hydro-chloric acid is passed into this mixture of barium salts and water
until saturated.
Then we heat this mixture for about 2 hours at a reversed condenser, evaporate the
excess of hydro-chloric acid on the water bath, dissolve the residue in water, and filter
off the precipitate of barium sulphate, which has been formed by the action of hydro-
chloric acid on the barium sulphonates.
Then we neutralize the solution of the new sulpho-acid with barium carbonate, and
we obtain an evaporation of the barium salt solution, the dry barium salt which can
be further purified by recrystallization from alcohol.
The barium salt is easily soluble in water and in ethyl alcohol which has been
slightly diluted with water.
This new sulpho-acid, which is as stated, Mono-sulpho-acid has remarkable properties,
by which it can be easily distinguished from all other mono-sulpho-acids of alpha-
naphtol.
It does not, on nitration, lose its sulpho-group, but yields on treatment with nitric
acid, dinitro-sulpho-alpha naphtol, which none of the hitherto known mono-sulpho-acids
of alpha-naphtol, do: and this reaction forms a striking difference between our
sulpho-acid and the known ones.
L
It combines with diazo-compounds and forms valuable dye-stuffs.
We do not confine ourselves to the method above mentioned, the same result can be
1:4

page_text: We can modify the strength of sulphuric acid, used for the first step, taking fuming
sulphuric acid, instead of ordinary concentrated acid, and we can vary the temperature
and duration accordingly.
We can also decompose the barium salts with hydro-chloric acid in closed vessels
by heating, for instance, one part of the barium salts, with two parts of strong hydro-
chloric acid for 2 hours between 140° & 150° C., or even by heating the crude
mixture of the sulpho-acids and sulphuric acid, after dilution with a little water by
themselves, or after passing hydro-chloric acid gas into it, but we find that the specified
method gives us the best result.

page_text: We ADOLF LIEBMANN, Ph.D. and ARTHUR STUDER, Ph.D. both of 10 Marsden
Street Manchester in the County of Lancaster, Consulting Chemists, 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 :-
This process consists as follows:-
--
One part, by weight, of alpha-naphtol is mixed with four parts, by weight, of
concentrated sulphuric acid and then heated for about one hour at 130° C.
The resulting mixture of sulpho-acids is converted into their corresponding barium
salts. This mixture of barium salts is then suspended in about 10 parts of water, and
gaseous hydro-chloric acid is passed into this mixture of barium salts and water until
saturated.
Then we heat this mixture for about two hours at a reversed condenser, evaporate
the excess of hydro-chloric acid on the water bath, dissolve the residue in water, and
filter off the precipitate of barium sulphate, which has been formed by the action of
hydro-chloric acid on the barium sulphonates.
Then we neutralize the solution of the new sulpho-acid with barium carbonate, and
we obtain on evaporation of the barium salt solution, the dry barium salt which can
be further purified by recrystallization from alcohol.
The barium salt is easily soluble in water and in ethyl alcohol, which has been
slightly diluted with water.
This new sulpho-acid, which is as stated, a Mono-sulpho acid, has remarkable
properties, by which it can be easily distinguished from all other mono-sulpho acids of
alpha-naphtol.
It does not, on nitration, lose its sulpho-group, but yields on treatment with nitric
acid dinitro-sulpho-alpha-naphtol, which none of the hitherto known mono-sulpho
acids of alpha-naphtol, do, and this reaction forms a striking difference between our
sulpho-acid and the known ones.
It combines with diazo-compounds and forms valuable dye-stuffs.
We do not confine ourselves to the method above-mentioned, the same result can be
achieved in different ways.
We can modify the strength of sulphuric acid, used for the first step, taking fuming
sulphuric acid, instead of ordinary concentrated acid, and we can vary the temperature
and duration accordingly.
We can also decompose the barium salts with hydro-chloric acid in closed vessels
by heating, for instance, one part of the barium salts, with two parts of strong hydro-
chloric acid for two hours between 140° and 150° C. or even by heating the crude
mixture of the sulpho-acids, and sulphuric acid, after dilution with a little water by

page_text: themselves, or after passing hydro-chloric acid gas into it, but we find that the specified
method gives us the best results.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
The production of a new mono-sulpho acid of alpha naphtol, with the properties
and prepared in the manner as hereinbefore specified.