The Manufacture of a New Alpha-naphthol-disulphonic-acid.
Year: 1888

page_text: Date of Application, 26th Mar., 1888
Complete Specification Left, 18th Dec., 1838
Complete Specification Accepted, 29th Jan., 1889
[Communicated from abroad by THE ACTIEN GESELLSCHAFT FÜR ANILIN FABRIKATION,
of Berlin, in the German Empire, Manufacturing Chemists.]
The Manufacture of a New Alpha-naphthol-disulphonic-acid.
I, CHARLES DENTON ABEL of No. 28 Southampton Buildings, Chancery Lane in
the County of Middlesex, Consulting Engineer and Patent Agent do hereby declare
the nature of this invention to be as follows:-
If Naphthaline-disulphonic acid as obtained by treating naphthaline with sulphuric
acid-monochlorhydrine, or fuming sulphuric acid at a temperature of from 30
to 60° Celsius, is subject to a treatment with nitric acid, two nitro-naphthaline-
disulphonic acids of an iso neric constitution are formed. By reducing these nitro-
compounds two isomeric amido-naphthaline-disulphonic acids are obtained, which can
be separated by forming their sodium salts and crystallising the same from a
concentrated solution in water. The amido-naphthaline-di-sulphonic acid, the sodium
salt of which is less soluble in water corresponds to the alpha-naphtol disulphonic-acid
of German Letters Patent No. 40571. If this amido-naphthaline-disulphonic-acid is
separated by filtration, the filtered solution contains a new amido-naphthaline-
disulphonic acid, which precipitates in small crystals when hydrochloric-acid is
added.
For the production of this new amido-naphthaline-disulphonic acid and the cor-
responding naphthol-disulphonic acid the following method can be recommended.
To 20 kilos of naphthaline 100 kilos of fuming sulphuric acid, which contain
23 per cent. of sulphurous anhydride, are gradually added. The naphthaline is stirred
continually and the temperature carefully kept below 60° Celsius. The melt forms
at one time of the operation a clear liquid from which the formed naphthaline-di-
For the now
sulphonic acid crystallises as soon as the operation is completed.
following treatment with nitric acid, the melt is carefully cooled with ice water, after
which 14 kilos of nitric acid of 45° Be are gradually poured to it. During this
reaction the temperature is kept below 40° Celsius and the mixture stirred without

page_text: interruption. After the reaction is completed, the melt is dissolved in 1,000 Litres of
cold water and milk of lime is added to it until the liquid is neutralized. Hereupon
the mixture is heated up to its boiling point, the sulphate of lime which has been
formed is separated by filteration and the resulting solution containing the lime salts
of the nitro naphthaline, disulphonic acids is concentrated. The nitro naphthaline
disulphonic acids are converted into the corresponding amido naphthaline-disulphonic
acids by reduction with iron and sulphuric acid. As soon as this reaction is completed,
milk of lime is added to the boiling mixture. By filtration a solution results which
contains the lime salts of the amido-naphthaline-disulphonic acids. By treating with
sodium carbonate, the lime salts are converted into sodium salts. The filtered solution
of the sodium salts is concentrated up to crystallisation. After cooling, the neutral
sodium salt of that amido-naphthaline-disulphonic acid which corresponds to the
naphthol disulphonic acid of German Letters Patent No. 40571, becomes precipitated
and is separated by filtration. To the filtered solution hydrochloric acid is added in
excess, which causes the acid sodium-salt of the new amido-naphthaline-disulphonic
acid to be precipitated. This is filtered and dried.
In order to obtain the new substance in the form of crystals, it is dissolved in five
parts of boiling water, when, after cooling, it will be obtained in long white needles.
Investigation has shown that the new acid is expressed by the formula.
If the substance is subject to destructive distitiation in the presence of me, alpha-
naphthylamine is produced.
In order to produce the corresponding alphanaphothol-disulphonic-acid the new
alpha-naphthanine-disulphonic acid is next converted into its diazo-compound. The
diazo-compound precipitates in colourless needles which are filtered, pressed and
suspended again in water, whereupon they are gradually poured into boiling water,
which has been acidulated with a small quantity of sulphuric acid. When the
conversion has been completed the liquid is neutralized by milk of lime, filtered, and
the lime salt of the new alphanaphthol disulphonic acid transformed into the sodium
salt by a solution of carbonate of sodium. The filtered solution of the sodium salt is
then concentrated and after cooling it is obtained in long colourless needles, differing
in this point considerably from the alphanaphthol-disulphonic acid of German Letters
Patent No. 40571 which, under similar circumstances crystallises in small white
leaflets.
To indicate yet another difference between the new alphanaphthol-disulphonic acid
and the naphthol-disulphonic acid of German Letters Patent No. 40571, it may be
stated that no yellow-dyestuff, soluble with difficulty, is obtained when the new
sulphonic acid is treated with nitric acid. By treating the naphthol-disulphonic acid
of German Letters Patent No. 40571 with nitric acid it is converted into the so called
"Brilliant yellow."
Finally it may be stated that the new naphthol-disulphonic acid also acts upon the
diazo-compounds of diphenyl, ditolyl stilbene etc. Blue dyestuffs are obtained by
these reactions, which dye cotton in a soap bath without any mordants.
Dated this 26th day of March 1888.
ABEL & IMRAY,
Agents for the Applicant.

page_text: I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery Lane, in
the County of Middlesex, Consulting Engineer and 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 :-
If naphthaline disulphonic acid as obtained by treating naphthaline with sulphuric
acid monochlorhydrine, or fuming sulphuric acid at a temperature below 100° Celsius
is subject to a treatment with nitric acid, two nitro naphthaline disulphonic acids of an
isomeric constitution are formed. By reducing these nitro compounds two isomeric
amido naphthaline disulphonic acids are obtained which can be separated by
forming their sodium salts and crystallising the same from a concentrated solution
in water.
The amido naphthaline disulphonic acid, the sodium salt of which is less soluble
in water corresponds to the alpha naphthol disulphonic acid of German Letters
Patent No. 40571.
If this amido naphthaline disulphonic acid is separated by filtration the filtered
solution contains a new amido naphthaline disulphonic acid which precipitates in small
crystals when hydrochloric acid is added.
For the production of this new amido naphthaline disulphonic acid and the cor-
responding naphthol disulphonic acid the following method can be recommended.
To 20 kilos of naphthaline 100 kilos of fuming sulphuric acid which contain
23 per cent. of sulphuric anhydride, are gradually added. The naphthaline is stirred
continually and the temperature carefully kept below 60° Celsius. The molt forms at
one time of the operation a clear liquid from which the formed naphthaline disulphonic
acid crystallises as soon as the operation is completed.
For the now following treatment with nitric acid the melt is carefully cooled with
ice water, after which 14 kilos of nitric acid of 45° Be are gradually poured to it.
During this reaction the temperature is kept below 40° Celsius and the mixture stirred
without interruption. After the reaction is completed the melt is dissolved in
1000 litres of cold water and milk of lime is added to it until the liquid is
neutralized.
Hereupon the mixture is heated up to its boiling point, the sulphate of lime which
has been formed is separated by filtration and the resulting solution containing the
lime salts of the nitro naphthaline disulphonic acids is concentrated.
The nitro naphthaline disulphonic acids are converted into the corresponding amido-
naphthaline disulphonic acids by reduction with iron and sulphuric acid.
As soon as
this reaction is completed, milk of lime is added to the boiling mixture. By filtration
a solution results which contains the lime salts of the amido naphthaline disulphonic
acids. By treating with sodium carbonate the lime salts are converted into sodium
salts. The filtered solution of the sodium salts is concentrated up to crystallisation.
After cooling, the neutral sodium salt of that amido naphthaline disulphonic acid
which corresponds to the naphthol disulphonic acid of German Letters Patent
No. 40571 becomes precipitated and is separated by filtration.
To the filtered solution hydrochloric acid is added in excess, which causes the acid
sodium salt of the new amido naphthaline disulphonic acid to be precipitated. This
is filtered and dried. In order to obtain the new substance in the form of crystals, it

page_text: is dissolved in five parts of boiling water, when after cooling it will be obtained in
long white needles. Investigation has shewn that the new acid is expressed by the
formula:-
--
naphthylamine is produced.
In order to produce the corresponding alpha naphthol disulphonic acid, the new
alpha naphthylamine disulphonic acid is next converted into its diazo-compound. The
diazo compound precipitates in colourless needles which are filtered, pressed and
suspended again in water whereupon they are gradually poured into boiling water
which has been acidulated with a small quantity of sulphuric acid. When conversion
has been completed the liquid is neutralized by milk of lime, filtered and the lime salt
of the new alpha naphthol disulphonic acid transformed into the sodium salt by a
solution of carbonate of sodium. The filtered solution of the sodium salt is then
concentrated and after cooling, it is obtained in long colourless needles, differing in
this point considerably from the alpha-naphthol disulphonic acid of German Letters
Patent No. 40571 which under similar circumstances crystallises in small white
leaflets.
To indicate yet another difference between the new alpha naphthol disulphonic acid
and the naphthol disulphonic acid of German Letters Patent No. 40571, it may be stated
that no yellow dyestuff soluble with difficulty is obtained when the new sulphonic acid
is treated with nitric acid. By treating the naphthol disulphonic acid of German
Letters Patent No. 40571 with nitric acid it is converted into the so called "Brilliant
yellow."
Finally it may be stated that the new naphthol disulphonic acid also acts upon the
diazo compounds of diphenyl, ditolyle, stilbene, etc.
Blue dyestuffs are obtained by these reactions which dye cotton in a soap bath
without any mordants.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The manufacture of a new alpha naphthol disulphonic acid which results from
the action of nitric acid upon naphthaline-disulphonic acid and the subsequent
treatment of the product in the manner herein set forth.
2. The process for the production of the new alpha naphthol disulphonic acid
referred to in the preceding claim, consisting in acting with nitric acid upon
naphthaline disulphonic acid, as obtained in treating naphthaline with sulphuric acid
monochlorhydrine or fuming sulphuric acid, then reducing the formed isomeric nitro-
naphthaline-disulphonic acids and after separating the amido naphthaline disulphonic
acids by their sodium salts, converting the disulphonic acid whose neutral salt is the
easier soluble in water, into the corresponding alpha naphthol disulphonic acid,
substantially as herein described.
Dated this 18th day of December 1888