The Production of Perichlornaphtoldisulpho Acid, and Disazo Dye-stuffs therefrom.
Year: 1894

page_text: Date of Application, 29th Jan., 1894
Complete Specification Left, 29th Oct., 1894-Accepted, 1st Dec., 1894
PROVISIONAL STEIT
The Production of Perichlornaphtoldisulpho Acid, and Disazo
Dye-stuffs therefrom.
I, SYDNEY PITT, of Sutton in the County of Surrey, Gentleman, (a communi-
cation to me from abroad by Leopold Cassella & Co., of 19 Liebigstrasse, Frankfort-
on-Main in the Empire of Germany) do hereby declare the nature of this
invention to be as follows:--
If the diazo compound of a, a, amidonaphtol B, ẞ disulpho acid which has
been designated by the letter H in the British Patent No. 17421, is brought into
contact with cuprous chloride (Cu,Cl₂) it is transformed into perichlornaphtol B, B
disulpho acid. This acid is a valuable intermediate product for the production of
azo dyestuffs. It may be considered as a chlorine substitute of the a₁ naphtol
B2 B3 disulpho acid which is obtained from that naphtylaminedisulpho acid which
is formed by nitrating and reducing ẞ₁ ẞ naphtalenedisulpho acid. The following
formula of the constitution
this
is sufficient to illustrate this connection. In order to investigate the influence of
chlorine, the azo derivatives which are obtained from the acid of
Specification, have to be compared with the known azo derivatives of a₁ naphtol
BB disulpho acid. It will then be found that by the atom of chlorine
entering into the peri position, the shade of the dye-stuffs is changed quite
remarkably (turning bluer), and that their fastness to washing is materially
increased.
:-
The acid may be produced for instance as follows:-
50 kilos. a, a amidonaphtol ẞ, ẞ, disulpho acid are transformed into the yellow
difficultly soluble diazo compound. The latter is filtered off and muriatic acid
of 10% is added. At a temperature of 10° C. a solution of 5 kilos. cuprous
chloride is then added and this temperature is maintained stirring well at the
same time until the yellow color has disappeared, and the solution is complete.
Then the copper is precipitated with sulphide of hydrogen, the sulphuret of
copper is filtered off and the filtrate is saturated with common salt at the boiling
point. When cold, the acid sodium salt of the thus formed chlornaphtoldisulpho
acid is precipitated in colorless crystals in almost theoretical quantity.
The acid salts of chlornaphtoldisulpho acid crystallize well. The neutral salts
are very easily soluble, their solutions show no fluorescence; by the action of
chloride of iron they take a dark green shade.
If combined with tetrazo bodies, it
The acid reacts easily with diazo bodies.
produces disazo dye-stuffs of great fastness and great purity of shade.
Example. 22-2 kilos. o. tolidine are transformed into the tetrazo compound,
and this is introduced into an alkaline solution of 75 kilos. perichlornaphtoldisulpho
acid. The mixture is left standing for 24 hours and by then heating it to 60° C.

page_text: a large portion of the dye-stuff is precipitated. It dyes unmordanted cotton a
blue shade.
From perichlornaphtoldisulpho acid also mixed disazo dye-stuffs can be
produced.
The application of this acid for non-symmetrical combinations is of course of
special value in such cases where pure shades are to be obtained. Thus it replaces
advantageously for instance the ẞ naphtol & disulpho acid in diamine blue black
which is the non-symmetrical product from diamidoethoxydiphenyle, naphtol-
S-disulpho acid and y amidonaphtolsulpho acid. For producing mixed combina-
tions the perichlornaphtoldisulpho acid may be used as well in the first place as in
the second one.
Example. 22.8 kilos. diamidoethoxydiphenyle are transformed into their tetrazo
compound. Then a neutral solution of 34 kilos. perichloruaphtoldisulpho acid is
added, and the mixture is introduced into a cold solution containing an excess of
soda. The red colored intermediate body is at once formed; to this a solution
of 24 kilos. as 'a, naphtolsulpho acid is added. After a short time the formation of
the dye-stuff is terminated. The dyestuff is precipitated with common salt. It
dyes unmordanted cotton a blue shade.
In the following table the shades of the most important combinations are
compiled:

page_text: The Production of Perichlornaphtoldisulpho Acid, and Disazo
Dye-stuffs therefrom.
1, SYDNEY PITT, of Sutton in the County of Surrey, Gentleman (a communi-
cation to me from abroad by Leopold Cassella & Co. of 19 Liebigstrasse,
Frankfort-on-Main in the Empire of Germany) 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 the diazo compound of a, a, amidonaphtol ẞ, ẞ, disulpho acid which has
been designated by the letter H in the British Patent No. 1742", is brought into
contact with cuprous chloride (Cu,Cl₂) it is transformed into perichlornaphtol
B, B, disulpho acid. This acid is a valuable intermediate product for the
production of azo dyestuffs. It may be considered as a chlorine substitute of
the a naphtol B, ẞ disulpho acid which is obtained from that naphtylamine-
disulpho acid which is formed by nitrating and reducing ß ß. naphtalenedisulpho
acid. The following formula of the constitution
is sufficient to illustrate this connection. In order to investigate the influence of
chlorine, the azo derivatives which are obtained from the acid of this Specification,
have to be compared with the known azo derivatives of a, naphtol ẞ, ẞ, disulpho
acid. It will then be found that by the atom of chlorine entering into the peri
position, the shade of the dye-stuffs is changed quite remarkably (turning bluer),
and that their fastness to washing is materially increased.
The acid may be produced for instance as follows:-
50 kilos. as a amidonaphtol ẞ, ẞ, disulpho acid are transformed into the yellow
difficultly soluble diazo compound. The latter is filtered off and muriatic acid
of 10% is added. At a temperature of 10° C. a solution of 5 kilos. cuprous
chloride is then added and this temperature is maintained stirring well at the same
time until the yellow color has disappeared, and the solution is complete. Then
the copper is precipitated with sulphide of hydrogen, the sulphuret of copper is
filtered off and the filtrate is saturated with common salt at the boiling point.
When cold, the acid sodium salt of the thus formed chlornaphtoldisulpho acid is
precipitated in colorless crystals in almost theoretical quantity.
The acid salts of chlornaphtoldisulpho acid crystallize well. The neutral
salts are very easily soluble, their solutions show no fluorescence; by the action of
chloride of iron they take a dark green shade.
The acid reacts easily with diazo bodies.
Example: 22.3 kilos. of naphtionic acid are diazotised in the known manner and
the diazo-compound is introduced into the alkaline solution of 36 kilos. perichlor-
naphtoldisulpho-acid.

page_text: The dyestuff is precipitated by means of common salt from the solution in form
of a crystalline precipitate, which is filtered off and dried.
The dyestuffs thus produced dye wool bluish red shades.
Instead of diazonaphtalenesulpho acid other diazo compounds can be used with
a like result.
Example: 241 kilos. of dehydrothioparatoluidine are diazotised by means of
40 kilos. muriatic acid and 7 kilos. of nitrite of soda. The yellow solution of the
diazo compound is allowed to run into the solution of 36 kilos. perichlornaphtol-
disulpho acid which is kept alkaline by means of carbonate of soda. A dark red
solution is formed from which the coloring matter is precipitated by addition of
common salt.
If instead of dehydrothioparatoluidine similar compounds such as the so-called
primuline base, the dehydrothiometaxylidine or their sulpho acids are used the
method as described in the foregoing example and its result are not materially
altered.
Valuable dyestuffs are further obtained from the diazo-derivatives of amido-azo-
compounds.
Example: 20 kilos. of amidoazobenzene are diazotised in the usual manner and
the diazo compound is brought into the alkaline solution of 36 kilos. perichlornaphtol-
sulpho acid.
Immediately a dark red precipitate is formed which is filtered off and dried.
The dyestuff produced dyes bluish red shades on wool and mordanted cotton.
Example: 16-5 kilos. of diazo salicylic acid are allowed to react with 14.3 kilos.
of alpha naphtylamine. The amidoazo-compound thus produced is diazotised
and the diazoazo compound is brought together with 36 kilos. perichlornaphtol-
disulpho acid in presence of carbonate of soda.
A black dyestuff is formed which with or without the aid of chromic mordants
dyes wool blackish blue shades.
If the new acid is combined with tetrazo bodies, it produces disazo dyestuffs of
great fastness and great purity of shade.
Example: 212 kilos o. tolidine are transformed into the tetrazo compound,
and this is introduced into an alkaline solution of 75 kilos. perichlornaphtoldisulpho
acid. The mixture is left standing for 24 hours and by then heating it to 60° C.
a large portion of the dyestuff is precipitated. It dyes unmordanted cotton a
blue shade.
From perichlornaphtoldisulpho acid also mixed disazo dyestuffs
produced.
can be
The application of this acid for non-symmetrical combinations is of course of
special value in such cases where pure shades are to be obtained. Thus it replaces
advantageously for instance the naphtol & disulpho acid in diamine blue black
which is the non-symmetrical product from diamidoethoxydiphenyle, ẞ naphtol-
8 disulpho acid and amidonaphtolsulpho acid. For producing mixed combinations
the perichlornaphtoldisulpho acid may be used as well in the first place as in the
second one.
:
Example 22-8 kilos. diamidoethoxydiphenyle are transformed into their tetrazo
compound. Then a neutral solution of 34 kilos. perichlorna phtoldisulpho acid is
added, and the mixture is introduced into a cold solution containing an excess of
soda. The red colored intermediate body is at once formed; to this a solution
of 24 kilos. a₁ ag naphtolsulpho acid is added. After a short time the formation o
the dyestuff. is terminated. The dyestuff is precipitated with common salt. I
dyes unmordanted cotton a blue shade.

page_text: In the following table the shades of the most important combinations are
compiled:
Dye-stuff from 1 molecule perichlornaphtol-
disulpho acid, one molecule of the tetrazo
compound of:
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. Producing perichlornaphtoldisulpho acid, by bringing the diazo derivative of
a₁ as amidonaphtol ẞ, ẞ, disulpho acid H into contact with cuprous chloride
substantially as described.
2. Producing azo-dyestuffs by combining diazo bodies with the perichlornaphtol-
disulpho acid substantially as described.
3. Producing disazo dyestuffs by combining one molecule of a tetrazo derivative
of a paradiamine either with two molecules of perichlornaphtoldisulpho acid or
with one molecule of the said acid and one molecule of another amine for phenol
substantially as described.
4. As new products the perichlornaphtoldisulpho acid and the new coloring
matters hereinbefore described.
Dated this 26th day of October 1894
SYDNEY PITT.