IMPROVEMENTS IN THE MANUFACTURE OF SEVERAL MONO-SULPHO ACIDS OF BETA-NAPHTYLAMINE
Year: 1884

page_text: I EMIL ELSÄSSER of Brögler Strasze Barmen in the Kingdom of Prussia, Chemist
to the Farben-Fabrik von Dahl and Company of Barmen in the Kingdom of
Prussia do hereby declare the nature of said invention for "IMPROVEMENTS IN
THE MANUFACTURE OF SEVERAL MONO-SULPHO ACIDS OF BETA-NAPHTYLAMINE
" to
be as follows:-
I dissolve one part of Beta-naphtylamine in three times its quantity of fuming
sulphuric acid (containing fifteen to twenty per cent anhydrous acid) at forty to
fifty degrees centigrade and heat the same to seventy to seventy five degrees
centigrade so long that a test solution in water becomes or remains clear on the
addition of ammonia. Half to three quarters of an hour generally is sufficient for
warming. I then add five times the quantity of cold water and filter separating
thereby the difficultly soluble Beta-naphtylamin mono-sulpho acids from the more
readily soluble portions. The residue is pressed out and by boiling with a solution
of soda is transformed into the corresponding sodium salt, which is dried by the
evaporation of the moisture. The dry salt contains three Beta-naphtylamin
mono-sulpho acids.
In order to separate the salts of these three acids the mixture is allowed to
simmer for about one hour with six times its quantity of alcohol of 93 to 96 degrees
Beaume, and is then filtered.
The residue consists of the sodium salt of a Beta-naphtylamine-mono sulpho
acid (I), which is difficultly soluble in both hot and cold water but whose Barium
salt is readily soluble in water from which it crystallizes out in large connected
columns.
The filtrate is evaporated and the residue consisting of the sodium salts of two
Beta-naphtylamine mono sulpho acids is dissolved in water and hydrochloric or
other mineral acid is added by which both the Beta-naphtylamine mono-sulpho
acids are precipitated. These are dissolved by boiling with carbonate of lime
of strontium or of barium, the solution is then filtered and allowed to stand
twenty four hours, during which a difficultly soluble mono-sulpho salt of Beta-
naphtylamine II is precipitated in small quantity whilst the more readily soluble
salt remains in solution. This readily soluble salt contains an hitherto unknown
mono-sulpho acid of Beta-naphtylamine III.

page_text: The free acid is very difficultly soluble in both hot and cold water in which
however its salts are readily soluble and crystallize out from the same in small
indistinct papillary forms.
The separation of the readily soluble sodium salt extracted with warm alcohol
can also be effected by the different solubility of the same in cold alcohol.
If the warm alcoholic solution is filtered and the filtrate allowed to stand, the
sodium salt of one of the acids is for the most part precipitated, whilst that of the
last described remains in solution and can be obtained by the evaporation of
the alcohol.
The herein described method of separation can also be applied to the difficultly
soluble acids obtained in the manner already known by treating Beta-naphtylamine
at 100 to 105 degrees with sulphuric acid containing 97 to 98 per cent of
mono-hydrous acid.
This mixture contains the same acids but in quite different proportions to that
obtained by treating Beta-naphtylamine with fuming sulphuric acid.
J. W. HARDING,
Agent for the Applicant.

page_text: I EMIL ELSÄSSER of Brögler Strasze Barmen in the Kingdom of Prussia Chemist
to the Farben-Fabrik von Dahl and Company of Barmen in the Kingdom of
Prussia do hereby declare the nature of my said Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF SEVERAL MONO-SULPHO-ACIDS OF BETA-NAPHTYLAMINE
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
I dissolve 1 part of Beta-naphtylamine in three times its quantity of fuming
sulphuric acid (containing 15 to 20 per cent of anhydrous acid) at 40 to 50 degrees
centigrade, and heat the same to 70 to 75 degrees centigrade so that a test solution
becomes or remains clear on the addition of ammonia. From one half to three
quarters of an hour is generally sufficient for warming. I then add five times the
quantity of cold water and filter, separating thereby the difficultly soluble mono-
sulpho-acids of Beta-naphtylamine from the more readily soluble portions. The
residue is pressed out and by boiling with a solution of soda is transformed into
the corresponding sodium salt, which is dried by evaporation of the moisture.
This dry salt contains three mono-sulpho-acids of Beta-naphtylamine.
In order to separate the salts of these three acids, the mixture is allowed to
simmer for about 1 hour with six times its quantity of alcohol of 93% to 96°
Beaume, and is then filtered.
о
°
The residue, which is easily soluble in water, consists of the sodium salt of a
mono-sulpho-acid I of Beta-naphtylamine which is difficultly soluble in both hot
and cold water and whose Barium Salt is readily soluble in water from which it
crystallizes out in large connected columns.
The filtrate is evaporated, and the residue consisting of the sodium salts of two
mono-sulpho-acids of Beta-naphtylamine is dissolved in water and hydrochloric
or other mineral acid is added by which both the mono sulpho-acids of Beta-
naphtylamine are precipitated. These are dissolved by boiling with carbonate of
Jime, strontium, or barium, the solution is then filtered and allowed to stand
24 hours during which a difficultly soluble mono-sulpho-acid II of Beta-naphty-
lamine is precipitated in small quantity, whilst the more readily soluble salt remains
in solution. This readily soluble salt contains an hitherto unknown mono-sulpho
acid of Beta-naphtylamine III.
The free acid is very difficultly soluble in both hot and cold water, in which
however, its salts are readily soluble and crystallize out from the same in small
indistinct papillæ.
The separation of the readily soluble sodium salt, extracted with warm alcohol,
can also be effected by the different solubility of the same in cold alcohol.
If the warm alcoholic solution is filtered, and the filtrate allowed to stand, the
sodium salt of one of the acids is for the most part precipitated, whilst that of the
last described remains in solution, and can be obtained by the evaporation of
the alcohol.
The herein described method of separation can also be applied to the difficultly
soluble acids, obtained in the manner already known, by treating Beta-naphtylamine
at 100 to 105 degrees with sulphuric acid containing 97 to 98 per cent of mono-
bydrous acid.
This mixture contains the same acids but in quite different proportions to that
obtained by treating Beta-naphtylamine with fuming sulphuric acid.

page_text: Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is.
The methods of producing or manufacturing the three mono sulpho acids
(indicated as I II and III) of Beta-naphtylamine substantially as herein set forth.
· Dated this Eleventh day of October 1884.