stuffs obtained
Year: 1892

page_text: Date of Application, 1st Sept., 1892
Complete Specification Left, 30th May, 1893-Accepted, 29th July, 1893
amidophenol, and to violet-black dye stuffs obtained therefrom.
If chlorhydrate of nitrosodimethylaniline is mixed with a solution of bisulphite
of sodium a product of condensation is obtained of one molecule of nitrosodimethyl-
aniline with two molecules of bisulphite of sodium easily soluble in water and
having the formula :-
(CH3)2NCH - N = (SO,Na),.
Further I have found that under certain circumstances the two sulpho groups
combined with nitrogen take the place of two hydrogens in the benzene under
simultaneous separation of dimethylamine and that I thus obtain finally two
isomeric disulpho acids of para-amidophenol which I distinguish respectively as
a and B acid.
Example 1. Production of a-para-amidophenol disulpho acid :-5 kilogrammes of
chlorhydrate of nitrosodimethylaniline are added whilst stirring to 15 kilogrammes
of a solution of bisulphite of sodium (38 Beaumé). The nitrosodimethylaniline salt
is quickly dissolved and the temperature raised to 55° C. The solution is filtered to
separate a resinous substance, then mixed with 23 kilogrammes of concentrated
muriatic acid and boiled by steam during two hours. When cold the primary
sodium salt of the a-para-amidophenol disulpho acid crystallizes in long silk like
needles which are separated from the acid solution containing the dimethylamine.
Example 2. Production of B-para-amidophenol disulpho acid :-Quite a different
disulpho acid of the para-amidophenol is obtained by evaporating the solution of
the nitrosodimethylaniline in bisulphite of sodium until it shews a temperature of
115° C. When cold I add to the solution some water and about the same volume
of muriatic acid and filter the primary sodium salt of the B-para-amidophenol
disulpho acid which crystallizes in a few hours; recrystallized from hot water it is
obtained in small short prisins.
Both disulpho acids shew in dilute alkaline solution a beautiful blue fluorescence.
Example 3. Production of violet-black dye stuff from the above a-para-amido-
phenol disulpho acid-5-7 kilogrammes of a paste of primary sodium salt of
a-para-amidophenol disulpho acid, corresponding to 2.69 kilogrammes of dry acid
are dissolved in 25 liters of water and diazotized by addition of 12 kilogrammes of
concentrated muriatic acid and a solution of 700 grammes of nitrite of sodium.
After a short time the solution of the diazo compound is poured into a solution of
1.79 kilogrammes of muriate of a-naphtylamine in 100 liters of water and the
mixture then heated to 80° C. When cold the amidoazo compound crystallizing
in blueish steel like needles is transformed into the diazoazo compound by addition
of ice and 700 grammes of nitrite of sodium; finally it is allowed to act upon
an alkaline solution of 14 kilogrammes of B-naphtol. The colouring matter
immediately formed, separates in black flocks and after boiling it is filtered,
pressed and dried. It dissolves in water with blue black colour and dyes wool
violet-black.

page_text: Similar dye stuffs are obtained by taking ẞ-naphtol, ẞ-monosulpho acid (Schäffer)
or 6-naphtylamine instead of ẞ-naphtol.
Dated this 1st day of September 1892.
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicant.
1
UL. The TITI OL
Basel, Switzerland, Colour Manufacturers, 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 invention relates to the production of two isomeric disulpho acids of para-
amidophenol and violet black dye stuff's obtained therefrom.
If chlorhydrate of nitroso dimethylaniline is mixed with a solution of bisulphite
of sodium a product of condensation is obtained of one molecule of nitroso dimethyl-
aniline with two molecules of bisulphite of sodium easily soluble in water and
having the formula :— .
=
-
(CH) NC.H. - N (SO₂Na),.
Further, I have found that under certain circumstances the two sulpho groups
combined with nitrogen take the place of two hydrogens in the benzene under
simultaneous separation of dimethylamine and that I thus obtain finally two
isomeric disulpho acids of para-amidophenol which I distinguish respectively as
a and acid.
Example 1. Production of a-para-amidophenol disulpho acid :-5 kilogrammes of
, chlorhydrate of nitroso dimethylaniline are added whilst stirring to 15 kilogrammes
of a solution of bisulphite of sodium (38° Beaumé). The nitroso dimethylaniline
salt is quickly dissolved and the temperature raised to 55° C. The solution is
filtered to separate a resinous substance, then mixed with 23 kilogrammes of
concentrated muriatic acid and boiled by steam during two hours.
When cold the
primary sodium salt of the a-para-amidophenol disulpho acid crystallizes in long
silk like needles which are separated from the acid solution containing the
dimethylamine.
Example 2. Production of B-para-amidophenol disulpho acid :-Quite a different
disulpho acid of the para-amidophenol is obtained by evaporating the solution of
the nitroso dimethylaniline in bisulphite of sodium until it shews a temperature of
115° C. When cold, I add to the solution some water and about the same volume
of muriatic acid and filter the primary sodium salt of the B-para-amidophenol
disulpho acid which crystallizes in a few hours; recrystallized from hot water it is
obtained in small short prisms.
Both disulpho acids shew in dilute alkaline solution a beautiful blue fluorescence.
Example 3. Production of violet-black dye stuff from the above a-para-amido-
phenol disulpho acid-57 kilogrammes of a paste of primary sodium salt of
a-para-amidophenol disulpho acid corresponding to 2.69 kilogrammes of dry acid
are dissolved in 25 liters of water and diazotized by addition of 12 kilogrammes of
concentrated muriatic acid and a solution of 700 grammes of nitrite of sodium.
After a short time the solution of the diazo compound is poured into a solution of
1.79 kilogrammes of muriate of a-naphtylamine in 100 liters of water and the
mixture then heated to 80° C. When cold the amido azo compound crystallizing
in blueish steel like needles is transformed into the diazo azo compound by addition
of ice and 700 grammes of nitrite of sodium; finally it is allowed to act upon
an alkaline solution of 14 kilogrammes of ẞ-naphtol. The colouring matter

page_text: immediately formed separates in black flocks and after boiling it is filtered,
pressed and dried. It dissolves in water with blue-black colour and dyes wool
violet-black.
'
Similar dye stuffs are obtained by taking ẞ-naphtol, B-monosulpho acid (Schäffer)
or B-naphtylamine instead of ẞ-naphtol.
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 :-
The production of two isomeric disulpho acids of para-amidophenol and violet
black dye stuff's obtained therefrom, substantially as described.
Dated this 30th day of May 1893.
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicant.