Improvements in the Manufacture of a, a,-dihydroxynaphthalene- a-monosulpho Acid.
Year: 1894

page_text: Date of Application, 19th Jan., 1894
Complete Specification Left, 19th Oct., 1894-Accepted, 24th Nov., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by THE FARBENFABRIKEN, vormals FRIEDRICK
BAYER & Co., of Elberfeld, in the Empire of Germany.]
Improvements in the Manufacture of a, a,-dihydroxynaphthalene-
a-monosulpho Acid.
I HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows :-
My foreign correspondents have described in the Specification of Letters Patent
No. 13665, dated 29th August 1889, a process for producing a a-dihydroxynaph-
thalene-a-mono sulpho acid, which process consists in melting with alkalies the
a-naphthol disulpho acid S, the composition of which is represented by the
formula:
The same result is also obtained if, as my foreign correspondents have likewise
found, the corresponding 8-naphthosultone sulpho acid is melted with alkalies.
The researches of my foreign correspondents have now shown, that the aforesaid
aa-dihydroxynaphthalene-a-mono sulpho acid, which is of high technical value
for the production of colouring matters, can also be produced by means of the
naphthalene-a, a, disulpho acid (naphthalene 1: 4-disulpho acid) described in the
Specification of Letters Patent No. 11865°.
According to the researches of my foreign correspondents (see the German
Patent No. 70857, dated 26th June 1892), this naphthalene-a, a-disulpho acid is,
by nitrating and subsequently reducing, converted into a-naphthylamine-a₁ a₂-
disulpho acid.
My foreign correspondents have now found, that a₁ a-dihydroxynaphthalene-a-
monosulpho acid is formed with great readiness, if the aforesaid a, naphthylamine-
as a mono sulpho acid, or salts thereof, are heated with alkalies in open or closed
vessels at about 200 degrees Centigrade. The above a naphthylamine-a, a₂-mono-
sulpho acid is, by diazotisation, and by subsequently boiling the diazo product so
formed with water or acid, converted into a sultone sulpho acid. On heating the
latter acid or the naphtholdisulpho acid (which results from the sultone disulpho
acid by melting with alkalies), or salts thereof, with alkalies, a reaction takes
place at a comparatively low temperature, say, from 170 to 180 degrees Centigrade
(as the researches of my foreign correspondents have now shown), one sulpho group
being displaced by the hydroxylic group, and the above a, a, dihydroxynaphtha-
lene-a-monosulpho acid being thus produced.

page_text: Owing to the reactions above referred to, the compositions of the nitro and
amidonaphthalene-ai as disulpho acid (obtained from naphthalene-a, a,-disulpho
acid), and the corresponding naphthosultone sulpho acid and naphtholdisulpho acid,
must be represented by the following respective formulæ, viz.:-
ȧ₁ α-DIHYDROXYNAPHTHALENE-a-MONO SULPHO ACID FROM a NAPHTHY1.-
AMINE-α₁ α-DISULPHO ACID.
1 part of a naphthylamine-a as disulphonate of sodium is mixed with 3 parts of
soda-lye (containing 60 per cent. of real soda), and the mixture is heated, during
24 hours, at 250 degrees, in a vessel capable of withstanding pressure. The melted
mass is dissolved in the requisite quantity of muriatic acid (20 per cent.), and the
resulting liquid is allowed to cool. The above mentioned a₁ a dihydroxynaphtha-
lene-a-mono sulpho acid is thus formed, and separates in crystals.
As described in the Specification of the aforesaid Letters Patent No. 13665
of 1889, the a naphthol disulpho acid S is, by melting with alkalies, easily
converted into a₁ a-dihydroxynaphthalene-a-mono sulpho acid, and according to
the researches of my foreign correspondents, the new aforesaid a naphthol
aa, disulpho acid is also transformed with great ease, and in theoretical amount,
into a, a, dihydroxynaphthalene-a-monosulpho acid, whereas the isomeric as a di-
hydroxynaphthalene sulpho acid is not produced during this operation, which is the
more surprising as the a, a,-naphthol sulpho acid is, by melting with alkalies,
converted into dihydroxynaphthalene with greater ease than is the α a₁ naphthol
sulpho acid.
.
One method of transforming a, uaphthol-a, a, disulpho acid into a₁ a dihydroxy-
naphthalene a mono sulpho acid, is illustrated by the following example. The
parts are by weight.
EXAMPLE B.
q₁ a DIHYDROXYNAPHTHALENE-a-MONO SULPHO ACID FROM a NAPHTHOL-
a₁ a DISULPHO ACID.
•
20 parts of the a naphthol a, a, disulphonate of sodium are mixed with 100 parts
of soda-lye (containing 40 per cent. of soda), and the resulting liquid is heated at
from 170 to 200 degrees Centigrade, under pressure, until a sample taken out after
being dissolved in dilute acetic acid, and evaporating the sulphurous acid, does not
shew an increase in the formation of dyes on the addition of diazo compounds. At
this stage, the melted mass is allowed to cool, and the a₁ a dihydroxynaphthalene-
a-mono sulpho acid is then isolated in a suitable manner.
In order to produce the a₁ a-dihydroxynaphthalene-a-mono sulpho acid by means
of the new processes hereinbefore defined, my foreign correspondents do not limit

page_text: themselves to the directions given in the above two examples, as the mode of
working can be varied; for instance, the melting can also be effected in open
vessels, and the soda employed can be replaced by potassa or the like.
Dated this 19th day of January 1894.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of a a-dihydroxynaphthalene-
a-monosulpho Acid.
I HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, 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 :-
My foreign correspondents have described in the Specification of Letters Patent
No. 13665, dated 29th August 1889, a process for producing alpha, alpha,
dihydroxynaphthalene alpha monosulphonic acid, which process consists in acting
with alkalies on the alpha naphtholdisulphonic acid of the composition represented
by the formula :
The same result is obtained, if, as my foreign correspondents have also found,
the corresponding delta naphthosultonesulphonic acid is fused with alkalies.
The researches of my foreign correspondents have now shown, that the aforesaid
alpha, alpha, dihydroxynaphthalene alpha monosulphonic acid, which is of high
technical value for the production of colouring matters, can also be prepared by
means of the naphthalene-alpha, alpha, disulphonic acid (naphthalene 1.4 disulphonic
acid) described in the Specification of Letters Patent No. 11865".
According to the researches of my foreign correspondents (see the German
Patent No. 70857, dated 26th June 1892), this naphthalene-alpha, alpha, disulphonic
acid is converted, by nitration and subsequent reduction, into alpha, naphthylamine
alpha, alpha, disulphonic acid.
My foreign correspondents have now found that alpha, alpha-dihydroxynaph-
thalene-alpha-monosulphonic acid is formed with great readiness, if the aforesaid.
alpha, naphthylamine alpha, alpha, disulphonic acid, or salts thereof, are heated
with alkalies in open or closed vessels at about 200 degrees Centigrade. By
diazotizing the said alpha, naphthylamine alpha, alpha, disulphonic acid, and
subsequently boiling the diazo derivative with water or acid, it is converted into a
sultone sulphonic acid. On heating the latter acid, or the naphtholdisulphonic
acid formed from the sultone mono-sulphonic acid. by fusion with alkalies, or salts
thereof, with alkalies, action takes place at a comparatively low temperature, say,
from 170 to 180 degrees Centigrade (as the researches of my foreign correspondents
have now shown), one sulphonic group being displaced by hydroxyl; the above
mentioned alpha, alpha, dihydroxynaphthalene alpha monosulphonic acid being
thus produced.

page_text: The composition of the nitro and amidonaphthalene alpha, alpha, disulphonic
acid (obtained from naphthalene alpha, alpha, disulphonic acid), and the corre
sponding naphthosultone sulphonic acid and naphtholdisulphonic acid, must
consequently be represented by the following formulæ respectively, viz. :-
The production of alpha, alpha, dihydroxynaphthalene-alpha mono-sulphonic
acid from alpha, naphthylamine alpha, alpha, disulphonic acid, is illustrated by the
following example, the parts being by weight.
ALPHA ALPHA DIHYDROXYNAPHTHALENE ALPHA MONOSULPHONIC ACID
FROM ALPHA NAPHTHYLAMINE ALPHA, ALPHA, DISULPHONIC ACID.
1 part of alpha, naphthylamine alpha, alpha, disulphonate of sodium is mixed
with 3 parts of soda lye (containing 60 per cent. of caustic soda), and the mixture
is heated during 24 hours, at 250 degrees C., in a vessel capable of withstanding
pressure. The melted mass is dissolved in the requisite quantity of muriatic acid
(20 per cent.), and the liquid is allowed to cool. The sodium salt of alpha, alpha
dihydroxynaphthalene alpha monosulphonic acid then separates in crystals.
As described in the Specification of the aforesaid Letters Patent No. 13665 of
1889, the alpha naphthol disulphonic acid S is easily converted, by fusion with
alkalies, into alpha, alpha, dihydroxynaphthalene-alpha-monosulphonic acid, and
according to the researches of my foreign correspondents, the aforesaid new alpha.
naphthol alpha, alpha, disulphonic acid is also transformed, with great ease, and in
theoretical amount, into alpha, alpha, dihydroxynaphthalene-alpha-monosulphonic
acid, but the isomeric alpha, alpha, dihydroxynaphthalene sulphonic acid is not
produced during this operation, which is the more surprising, as the alpha, alpha,
naphthol sulphonic acid is converted, by fusion with alkalies, with greater ease,
into dihydroxynaphthalene, than is alpha, alpha, naphthol sulphonic acid.
One method of transforming alpha naphthol alpha, alpha, disulphonic acid into
alpha, alpha, dihydroxynaphthalene alpha monosulphonic acid, is illustrated by the
following example. The parts are by weight.
ALPHA ALPHA DIHYDROXYNAPHTHALENE ALPHA MONOSULPHONIC
FROM ALPHA NAPHTHOL ALPHA ALPHA, DISULPHONIC ACID.
ACID
20 parts of alpha, naphthol alpha, alpha, disulphonate of sodium are mixed with
100 parts of soda lye (containing 40 per cent. of caustic soda), and the liquid is 3
heated at from 170 to 200 degrees Centigrade, under pressure, until a sample which
has been deprived of sulphite by means of sulphuric acid, and then mixed with
sodium acetate, when mixed with diazo compounds no longer affords an increased
amount of dye-stuff. At this stage the melted mass is allowed to cool, and the
alpha, alpha, dihydroxynaphthalene alpha monosulphonic acid is then isolated in a
suitable manner.

page_text: In order to produce alpha, alpha, dihydroxynaphthalene alpha monosulphonic
acid by means of the new processes hereinbefore defined, my foreign correspondents.
do not limit themselves to the directions given in the above two examples, as the
mode of working can be varied; for instance, the fusion can also be effected in open
vessels, and instead of soda, potash or the like can be used.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me from
abroad, I declare that what I claim is :-
1. The production of alpha, alpha, dihydroxynaphthalene alpha monosulphonic
acid, by heating alpha, naphthylamine alpha, alpha, disulphonic acid, or salts
thereof, with alkalies, at temperatures above 200 degrees Centigrade.
2. The process for producing alpha, alpha, dihydroxynaphthalene alpha mono-
sulphonic acid, which process consists in heating alpha, naphthol alpha, alpha,
disulphonic acid, or salts thereof, with alkalies, at temperatures above 170 degrees
centigrade.