Improvements in the Manufacture of Naphthazarine and of New Intermediate Products related thereto.
Year: 1894

page_text: Date of Application. 22nd Feb., 1894
Complete Specification Left, 22nd Nov., 1894-Accepted, 22nd Dec., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Naphthazarine and of New
Intermediate Products related thereto.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of
Middlesex Gentleman do hereby declare the nature of this invention which has
been communicated to me from abroad by The Badische Anilin and Soda Fabrik of
Ludwigshafen-on-Rhine in the Empire of Germany to be as follows:--
Prior to this invention naphthazarine or alizarine black has been prepared
solely from 14' or alpha-dinitro-naphthalene.
My foreign correspondents have discovered that naphthazarine can also be
obtained by suitable processes from the 111 dinitro-naphthalene. Thus for
instance by heating this body with sulphuric acid in the presence of a reagent
having a reducing action such as those hereinafter set forth a new intermediate
product is obtained, which by boiling with dilute acids (or similar, so-called
saponifying treatment) is converted into naphthazarine.
Another process for the production of naphthazarine in which the same
intermediate product is formed consists in submitting the 111 dinitro-naphthalene
in a hot sulphuric acid solution to an electric current. The intermediate product
thus obtained can be, converted into naphthazarine in the manner herein before
indicated. This electrolytic process can also be applied to 1-41 dinitro-naphtha-
lene, hence when using this process, mixtures of the two dinitro-naphthalenes can
be taken, thus doing away with the necessity for separating and isolating these
compounds. Under these circumstances a mixture of intermediate products is
obtained which can readily be converted into naphthazarine.
FIRST PROCESS.
In the manufacture of naphthazarine from the 14' dinitro-naphthalene the best
results have been hitherto obtained by using a very concentrated or even fuming
sulphuric acid, but in the new process, using the 1.1' compound, an acid
containing about ninety-six per cent. or less real sulphuric acid H,SO can best
be employed.
In this process a large variety of reagents can be mixed with the sulphuric
acid, their action being to effect a reduction of the dinitro-naphthalene. As
instances I mention aromatic amines such as aniline, alpha-naphthylamine,
phenyl-hydrazine and the like also certain metals such as tin and iron and the
like and salts thereof possessing a reducing action but many other organic and
inorganic bodies possessing reducing properties can be used.
The following examples will serve to further illustrate the nature of this part
of the invention but I do not limit myself to these examples. The parts are by
weight.
Example 1. Mix about ten parts of 111 dinitro-naphthalene with about ten
parts of aniline and add the mixture to about two hundred parts of sulphuric acid
(containing about ninety-six per cent. real acid H,SO). Heat the mixture.to
about one hundred and twenty-five to one hundred and thirty degrees Centigrade
and maintain it at this temperature till the dinitro-naphthalene has all dis-
appeared.
This usually requires about eight or ten hours. A violet-red melt is obtained
whereas the naphthazarine melt from 14' dinitro-naphthalene according to the

page_text: old process is of a brown colour. Allow to cool, pour into ice-water, filter the
solution obtained which is of a violet-red colour and contains the new intermediate
product. Boil this dilute acid solution and then allow it to cool, the naphth-
azarine separates out. Collect in the usual way.
Instead of aniline in the above example a similar quantity of the other aromatic
amines herein before mentioned can be used.
Example 2. Add about ten parts of 11' dinitro-naphthalene to about two
hundred parts of sulphuric acid (containing about ninety five per cent. real
acid. H.SO) and heat the mixture to about one hundred and twenty-five
degrees Centigrade. Then add slowly about ten parts of tin and maintain the heat
for about ten hours. A red-violet melt is obtained. Pour this into ice-water,
filter, and work up, as described in Example 1.
If it be desired to isolate the new intermediate product add carefully to its
solution obtained as described in the foregoing examples, sufficient caustic
Boda to precipitate it. An excess of caustic soda redissolves the intermediate
product.
SECOND PROCESS.
The electrolytic process for the production of the new intermediate product can
best be illustrated by the following example.
Dissolve about one part of 11 dinitro-naphthalene in about twenty parts of
sulphuric acid (containing about ninety-five per cent. real acid H,SO,) and in a
vessel fitted with electrical connections heat the mixture to a temperature of about
one hundred and thirty degrees. In the said vessel immerse the cathode in the
hot solution of dinitro-naphthalene and the anode in sulphuric acid and keep these
two liquids separate by means of a diaphragm. Pass a current (of say about
fifteen ampères per square decimeter of electrode surface) through the cell and
continue this treatment until no dinitronaphthalene remains unchanged. Allow
to cool, pour the melt into water, filter, and convert the intermediate product into
naphthazarine as hereinbefore described.
If in the above example a mixture of the 11 and 1-4 dinitro-naphthalene be
used a mixture of intermediate products is obtained which, without any separation,
is readily converted in the same way into naphthazarine.
Dated this 22nd day of February 1894.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in the Manufacture of Naphthazarine and of New
Intermediate Products related thereto.
I, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of London
Gentleman do hereby declare the nature of this invention (which has been
communicated to me from abroad by The Badische Anilin & Soda Fabrik of
Ludwigshafen on Rhine 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 :-
Prior to this invention naphthazarine or alizarine black had been prepared
solely from 1'4' or alpha-dinitronaphthalene.
.
My foreign correspondents have discovered that naphthazarine cau also be
obtained by suitable processes from the 11' dinitro naphthalene. Thus for
instance, by beating this body with sulphuric acid in the presence of a reagent
having a reducing action such as those hereinafter set forth, a new intermediate

page_text: product is obtained, which by boiling with dilute acids (or similar so called
saponifying or more properly hydrolytic treatment) is converted into naphth-
azarine.
Another process for the production of naphthazarine in which the same
intermediate product is formed consists in submitting the 1.11 dinitro-naphthalene
in a hot sulphuric acid solution to an electric current. The intermediate product
thus obtained can be converted into naphthazarine in the manner hereinbefore
indicated. This electrolytic process can also be applied to 14' dinitro-
naphthalene, hence when using this process, mixtures of the two dinitro
naphthalenes can be taken, thus doing away with the necessity for separating and
isolating these compounds. Under these círcumstances a mixture of intermediate
products is obtained which can readily be converted into naphthazarine.
In the manufacture of naphthazarine from the 1.41 dinitro-naphthalene the best
results have been hitherto obtained by using a very concentrated or even fuming
sulphuric acid but in the new process using the 1.1' compound an acid
containing about ninety six per cent. or less real sulphuric acid H,SO, can best
be employed.
In this process a large variety of reagents can be mixed with the sulphuric
acid, their action being to effect a reduction of the dinitro-naphthalene. As
instances I mention aromatic amines such as aniline, alpha-naphthylamine,.
phenyl-hydrazine and the like, also certain metals such as tin and iron and the
like and salts thereof possessing a reducing action; but many other organic
and inorganic bodies possessing reducing properties can be used.
The following examples will serve to further illustrate the nature of this part
of the invention and the manner in which it can best be carried into practical.
effect but I do not limit myself to these examples. The parts are by weight.
Example 1. Mix about ten parts of 11 dinitro naphthalene with about ten
parts of aniline and add the mixture to about two hundred parts of sulphuric acid
(containing about ninety six per cent. real acid H.SO.). Heat the mixture to
about one hundred and twenty five to one hundred and thirty degrees Centigrade
and maintain it at this temperature till the dinitro naphthalene has all disappeared.
This usually requires about eight or ten hours. A violet-red melt is obtained
whereas the naphthazarine melt from 1.4¹ dinitro-naphthalene according to the
old process is of a brown colour. Allow the melt to cool and pour it into ice
water; filter the solution obtained, which is of violet-red colour and contains the
new intermediate product. Boil this dilute acid solution and then allow
it to cool, the naphthazarine separates out.
Collect in the usual way.
Instead of aniline in the above example a similar quantity of the other aromatic
amines herein before mentioned can be used.
Example 2. Add about ten parts of 1·11 dinitro naphthalene to about two
hundred parts of sulphuric acid (containing about ninety-five per cent. real
acid H,SO) and heat the mixture to about one hundred and twenty-five degrees
Centigrade. Then add slowly about ten parts of tin and maintain the heat for
about ten hours. A red-violet melt is obtained. Pour this into ice-water and
filter and work up as described in Example 1.
If it be desired to isolate the new intermediate product add carefully to its
solution obtained as described in either of the foregoing examples, sufficient
caustic soda to precipitate it. An excess of caustic soda redissolves the inter-
mediate product.

page_text: 1-1 dinitro-naphthalene in about twenty parts of sulphuric acid (containing about
"ninety five per cent. real acid H,SO) and in a vessel fitted with electrical
connections to a source of electricity heat the mixture to a temperature of about
"one hundred and thirty degrees. In the said vessel immerse the cathode in the
"hot solution of dinitro-naphthalene and the anode in sulphuric acid and keep these
two liquids separate by means of a porous diaphragm. Pass a current (of say
about fifteen amperes per square decimeter of electrode surface) through the cell
and continue this treatment until no dinitro naphthalene remains unchanged.
Allow the melt to cool and pour it into water filter and convert the intermediate
product into naphthazarine as hereinbefore described.
If in the above example a mixture of the 11' and 1-4 dinitro-naphthalene
be used, a mixture of intermediate products is obtained which without any
separation is readily converted in the same way into naphthazarine.
Having now particularly described and ascertained the nature of my inven
tion and in what manner the same is to be performed I declare that what I
claim is―
1. The manufacture of naphthazarine from 1·1' dinitro-naphthalene by heating
this body with sulphuric acid and a reagent having a reducing action hereinbefore
defined and subsequently hydrolysing the intermediate product formed all
substantially as herein before described.
✓ 2. The manufacture of naphthazarine by submitting 11' dinitro-naphthalene
either alone or mixed with 14 dinitro-naphthalene to electrolytic reduction in
hot sulphuric acid solution and converting the intermediate product formed into
naphthazarine by hydrolysis all substantially as hereinbefore described.
3. The production of a new intermediate product in the manufacture of
naphthazarine by heating 1·11 dinitro-naphthalene with sulphuric acid in the
'presence of a reagent having a reducing action as herein before defined.
•
4. The production of new intermediate products in the manufacture of naphth-
azarine by submitting 1·1' dinitro-naphthalene or a mixture of 11 dinitro
naphthalene and 1·4¹ dinitro-naphthalene to electrolytic reduction in hot sulphuric
acid solution.
5. The manufacture of naphthazarine and of the new intermediate products in
the manners described in the examples.
6. As new articles of manufacture the new intermediate products such as can be
obtained in the manner hereinbefore described.
Dated this 22nd day of November 1894.
JOHNSONS & WILL
WILLCOX
Agents.