Manufacture of a New Diamidonaphtol and Salts of the same.
Year: 1899

page_text: Date of Application, 8th Aug., 1899
Complete Specification Left, 8th May, 1900-Accepted, 23rd June, 1900
PROVISIONAL SPECIFICATION.
Manufacture of a New Diamidonaphtol and Salts of the same.
:
I, ROBERT BOLTON RANSFORD, of 41, Waldegrave Road, Upper Norwood, in the
County of Surrey, Gentleman, do hereby declare the nature of this invention
(which has been communicated to me from abroad by Leopold Cassella & Com-
pany, of Frankfort on Main, in the Empire of Germany) to be as follows:-
If the 2.7. amidonaphtol is combined with diazo bodies in an alkaline solution,
the azo group enters into the ortho position to the hydroxyl and by reduction of
the azo-dyestuffs thus obtained a diamidonaphtol of the following constitution is
formed
My correspondents have found that the salts of this new diami-
donaphtol possess the valuable property of yielding on wool deep brown
dyeings of great intensity and unsurpassed fastness if dyed in a boiling bath with
a simultaneous or subsequent addition of bichromates. None of the diami-
donaphtols hitherto known possess this property to a similar degree, not even the
closely related diamidonaphtol, obtained from the azoderivatives of the 2.7. amido-
naphtol formed in acid solution.
The new diamidonaphtol may be produced as follows:-
15.9 kilos 2.7. amidonaphtol are dissolved in muriatic acid and the base is
precipitated in a finely divided state by addition of soda. The diazo combination
from 9.3 kilos aniline is then allowed to run into the solution which is kept
alkaline by an excess of soda. . The separated, dyestuff is filtered off, the paste
stirred up with water, 20 kilos iron filings are introduced, the temperature raised

page_text: to the boiling point and muriatic acid is added gradually, whilst stirring well,
care being taken that the solution always shows an acid reaction. About 100 kilos
muriatic acid are required. After complete reduction the solution is filtered off
from the iron and the difficultly soluble sulphate of 1.7. diamido-2-oxynaphtalene
is precipitated from the filtrate by the addition of sulphate of sodium.
Or 15.9 kilos 2.7. amidonaphtol are diazotised with 6.9 kilos of nitrite and the
solution is made alkaline by addition of carbonate of soda. The azo-compound
separates in form of a dark precipitate. It is filtered off and gradually introduced
into a solution of tin salt. The diamidonaphtol thus produced is isolated by
means of the sulphate.
This salt is rather difficultly soluble in water, it crystallises in the form of
thin, nearly colourless needles. The free base obtained therefrom is rather
difficultly soluble in cold, more easily soluble in hot water; it crystallises in
brilliant leaves which melt at 220° C, whilst decomposing.
1000
Manufacture of a New Diamidonaphtol and Salts of the same.
I, ROBERT BOLTON RANSFORD, of 41, Waldegrave Road, Upper Norwood, in the
County of Surrey, Gentleman, do hereby declare the nature of this invention
(which has been communicated to me from abroad by Leopold Cassella & Com-
pany, of Frankfort-on-Main, in the Empire of Germany,) and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
If the 2.7. amidonaphtol is combined with diazo bodies in an alkaline solution.
the azo group enters into the ortho position to the hydroxyl and by reduction of
the azo-dyestuffs thus obtained a diamidonaphtol of the following constitution is
formed

page_text: My correspondents have found that the salts of this new diamidonaphtol of
which the chlorhydrate and the sulphate are especially useful possess the valuable
property of yielding on wool deep brown dyeings of great intensity and unsur-
passed fastness if dyed in a boiling bath with a simultaneous or subsequent
addition of bichromates. None of the diamidonaphtols hitherto known possess
this property. to a similar degree, not even the closely related diamidonaphtol,
obtained from the azo derivatives of the 2.7. amidonaphtol formed in acid
solution.,
The new diamidonaphtol may be produced as follows:
15.9 kilos 2.7. amidonaphtol are dissolved in muriatic acid and the base is
precipitated in a finely divided state by addition of soda.. The diazo combination
from 9.3 kilos aniline is then allowed to run into the solution which is kept
alkaline by an excess of soda. The separated dyestuff is filtered off, the paste
stirred up with water. 20 kilos iron filings are introduced, the temperature raised
to the boiling point and muriatic acid is added gradually, whilst stirring well
care being taken that the solution always shows an acid reaction. About 100 kilos
muriatic acid are required. After complete reduction the solution is filtered off
from the iron and the difficultly soluble sulphate of 1.7. diamido-2-oxynaphtalene
is precipitated from the filtrate by the addition of sulphate of sodium.
Or 15.9 kilos 2.7. amidonaphtol are diazotised with 6.9 kilos of nitrite and the
solution is made alkaline by addition of carbonate of soda. The azo-compound
separates in form of a dark precipitate. It is filtered off and gradually introduced
into a solution of tin salt. The diamidonaphtol thus produced is isolated by
means of the sulphate.
This salt is rather difficultly soluble in water, it crystallises in the form of
thin, nearly colourless needles. The free base obtained therefrom is rather
difficultly soluble in cold, more easily soluble in hot water; it crystallises in
brilliant leaves which melt at 220° C. whilst decomposing.
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:―
1. The production of 1.7. diamido-2-oxynaphtalene by reducing azo derivatives
obtained from 2.7. amidonaphtol in an alkaline solution or by reducing the sub-
stance which results from the action of alkalis on the 2.7. diazonaphtol substan-
tially as described.
2. The new diamidonaphtol and the herein described salts of the same.