A New Process for the Production of Naphthol Derivatives.
Year: 1899

page_text: ||[Communicated from abroad by the FARBENFABRIKEN VOTMAIS FRIEDRICH DAYER
& Co., of Elberfeld, Germany.]
A New Process for the Production of Naphthol Derivatives.
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:-
This invention relates to a valuable process for transforming naphthylamine
derivatives into the corresponding naphthol derivatives, which process consists
in first heating naphthylamine derivatives with sulphurous acid, or with salts
of this acid, (unstable intermediate products being produced), and, secondly sub-
jecting the said intermediate products to the action of suitable agents, such as
alkalies, acids, or the like, in order to transform the same into the naphthol
derivatives. Thus, for instance, on heating these intermediate products with
alkalies, ammonia is set free, the amido group being replaced by the hydroxy
group.
In order to illustrate the new process more fully, the following examples are
given, the parts being by weight.
TD A
PRODUCTION OF ALPHA-NAPHTHOL-ALPHA,-SULPHONIC ACID FROM ALPHA, NAPHTHYL-
AMINE ALPHA-SULPHONIC ACID.
A current of gaseous sulphurous acid (SO) is caused to pass slowly for 30
hours, at about from 95 to 100 degrees Centigrade, through a solution which
has been prepared from 10 parts of the sodium salt of alpha, naphthylamine-
alpha, sulphonic acid and 35 parts of water. Subsequently, the liquid is mixed
with hydrochloric acid until a test portion is found to change the color of a test
paper dyed with congo red into blue. The small quantity of unchanged naph-
thylamine sulphonic acid which has been separated by the mineral acid is filtered
off. The filtrate is rendered alkaline by means of caustic soda lye, and then
boiled until the development of ammonia ceases. Finally the solution is again
rendered acid by the addition of hydrochloric acid, and heated in order to remove
the sulphurous acid contained therein. The solution thus obtained, which con-
tains the alpha, naphthol alpha, sulphonic acid, can directly be used for the
production of dye-stuffs. In order to isolate the acid in the form of its acid
sodium salt, the solution can be saturated with common salt, the said sodium
salt being thus separated in the shape of small white leaves.
PRODUCTION OF ALPHA,-NAPHTHOL-ALPHA,-SULPHONIC ACID FROM ALPHA, NAPHTHYL-
AMINE ALPHA,-SULPHONIC ACID.
A current of gaseous sulphurous acid (SO2) is caused to pass slowly for 30
hours, at about from 95 to 100 degrees Centigrade, through a solution which
has been prepared from 10 parts of the sodium salt of alpha, naphthylamine-
alpha, sulphonic acid and 35 parts of water. Subsequently, the liquid is mixed
with hydrochloric acid until a test portion is found to change the color of a test
paper dyed with congo red into blue. The small quantity of unchanged naph-
thylamine sulphonic acid which has been separated by the mineral acid is filtered
off. The filtrate is rendered alkaline by means of caustic soda lye, and then
boiled until the development of aminonia ceases. Finally the solution is again
rendered acid by the addition of hydrochloric acid, and heated in order to remove
the sulphurous acid contained therein. The solution thus obtained, which con-
tains the alpha, naphthol alpha, sulphonic acid, can directly be used for the
production of dye-stuffs. In order to isolate the acid in the form of its acid
sodium salt, the solution can be saturated with common salt, the said sodium
salt being thus separated in the shape of small white leaves.

page_text: EXAMPLE B.
PRODUCTION OF ALPHA, NAPHTHOL-BETA-SULPHONIC ACID FROM ALPHA, NAPHTHYL-
AMINE BETA, SULPHONIC ACID.
A mixture prepared from 26.5 parts of the sodium salt of alpha,-naphthyl-
amine beta, sulphonic acid, 15 parts of water, and 75 parts of a sodium bisul-
phite solution of 40 degrees Baumé, is heated for about 15 hours in an enamelled
vessel provided with a stirring apparatus, at about from 120 to 150 degrees Centi-
grade, until an acidulated test portion is found to contain no longer a con-
siderable quantity of the unchanged naphthylamine sulphonic acid. The re-
action mixture is then further treated in the manner described in the foregoing
example, that is to say, it is rendered acid by means of hydrochloric acid, filtered,
rendered caustic-alkaline, and boiled in order to remove the ammonia, again
rendered acid, & afterwards freed from the sulphurous acid. The so-obtained
solution of alpha-naphthol beta,-sulphonic acid can be directly used for the pro-
duction of dye-stuffs.
The acid thus produced is identical with that which has been described by
Tumann Love "
L
310 R OnA
PRODUCTION OF ALPHA-ALPHA, DIHYDROXY-NAPHTHALENE-MONOSULPHONIC ACID
FROM ALPHA AMIDO-ALPHA, NAPHTHOL-ALPHA-SULPHONIC ACID.
A mixture prepared from 23.9 parts of alpha, amido-alpha, naphthol-alpha-
sulphonic acid and 60 parts of water is neutralized by means of caustic soda-lye.
Subsequently, 180 parts of a sodium bisulphite solution, of 40 degrees Baumé,
are added, and the resulting mixture is heated for about 24 hours at about 90
degrees Centigrade, in an enamelled vessel provided with a stirring apparatus,
until a test portion, on acidulating, no longer yields a cousiderable precipi-
tate of unchanged amido naphtholsulphonic acid. The reaction mixture is then
rendered acid by adding a mineral acid in the manner described in the above
Example A, and filtered. The filtrate is further treated as described in the said
example, viz., it is mixed with an excess of caustic soda lye, and boiled in order
to remove the ammonia, then again rendered acid, and freed from the sulphurous
acid contained therein. From the so-obtained solution of alpha, alpha, di-
hydroxynaphthalene alpha, sulphonic acid, this acid can be isolated in the usual
The acid thus produced exhibits the known properties.
manner.
EXAMPLE D.
PRODUCTION OF ALPHA, ALPHA-AMIDONAPHTHOL ALPHA, MONOSULPHONIC ACID.
A mixture prepared from 25 parts of the sodium salt of alpha, alpha, diamido-
naphthalene alpha, monosulphonic acid, 50 parts of water, and 60 parts of a sodium
bisulphite solution, of 42 degrees Baumé, is heated for about 4 hours with con-
tinuous stirring, at about from 80 to 90 degrees Centigrade. The mixture is then
rendered alkaline by means of caustic soda-lye, and boiled until the develop-
ment of ammonia ceases. Subsequently the liquid is acidulated, the alpha,
alpha, amidonaphthol alpha, monosulphonic acid being thus separated in the
shape of small white needles.
The process proceeds in an analogous manner if, instead of the naphthyl-
amine derivatives used in the above examples, other naphthylamine deriva-
tives are employed, or if other salts of sulphurous acid, such as potassium bisul-
phite, or the like, are used.
My foreign correspondents wish to point out that they do not intend to con-
fine themselves to the particulars given in the above specification, as the examples

page_text: contained therein are merely typical, and can be varied within wide limits. Thus,
for instance, instead of heating the alphanaphthylamine derivatives with the
sulphurous acid, or its salts, in open vessels, this reaction can also be performed
in autoclaves.
T
1
A
1000
NEWTON & SON,
Agents for the Applicant.
the new process more fully, the following examples are
given, the parts being by weight.
EXAMPLE A.
PRODUCTION OF ALPHA NAPHTHOL-ALPHA-SULPHONIC ACID FROM ALPHA, NAPHTHYL-
AMINE-ALPHA, SULPHONIC ACID.
A current of gaseous sulphurous acid (SO2) is caused to pass slowly for 30
hours, at about from 95 to 100 degrees Centigrade, through a solution which
has been prepared from 10 parts of the sodium salt of alpha, naphthylamine-
alpha, sulphonic acid and 35 parts of water. Subsequently, the liquid is mixed
with hydrochloric acid until a test portion is found to change the color of a test-
paper dyed with congo red into blue. The small quantity of unchanged naph-
thylamine-sulphonic acid which has been separated by the mineral acid, is filtered
off. The filtrate is rendered alkaline by means of caustic soda lye, and then
boiled until the development of ammonia ceases. Finally, the solution is again
rendered acid by the addition of hydrochloric acid, and heated in order to remove
the sulphurous acid contained therein. The solution thus obtained, which con-
tains the alpha, naphthol alpha, sulphonic acid, can directly be used for the
production of dye-stuffs. In order to isolate the acid in the form of its acid
sodium salt, the solution can be saturated with common salt, the said sodium
salt being thus separated in the shape of small white leaves.
EXAMPLE B.
PRODUCTION OF ALPHA, NAPHTHOL-BETA³ SULPHONIC ACID FROM ALPHA, NAPHTHYL-
AMINE-BETA- -SULPHONIC ACID.
A mixture prepared from 26.5 parts of the sodium salt of alpha,-naphthyl-
amine beta, sulphonic acid, 15 parts of water, and 75 parts of a sodium bisul-
phite solution of 40 degrees Baumé, is heated for about 15 hours in an enamelled
vessel provided with a stirring apparatus, at about from 120 to 150 degrees Centi-

page_text: grade, until an acidulated test portion is no longer found to contain a con-
siderable quantity of the unchanged naphthylamine sulphonic acid. The re-
action mixture is then further treated in the manner described in the foregoing
example, that is to say, it is rendered acid by means of hydrochloric acid, filtered,
rendered caustic-alkaline, and boiled in order to remove the ammonia, again
rendered acid, and afterwards freed from the sulphurous acid. The solution of
alpha,-naphthol-beta-sulphonic acid so obtained can be directly used for the pro-
duction of dye-stuffs.
The acid thus produced is identical with that which has been described by
Erdmann (see Annalen der Chemie, etc.," Vol. 275, p. 213 and 304.)
<
PRODUCTION OF Alpha,-alpha¸-DIHYDROXYNAPHTHALENE-ALPHA -SULPHONIC ACID
FROM ALPHA-AMIDO-ALPHA-NAPHTHOL-ALPHA SULPHONIC ACID.
A mixture prepared from 23.9 parts of alpha,-amido-alpha,, naphthol-alpha,-
sulphonic acid, and 60 parts of water is neutralized by means of caustic soda-lye.
Subsequently, 180 parts of a sodium bisulphite solution, of 40 degrees Baumé.
are added, and the resulting mixture is heated for about 24 hours, at about 90
degrees Centigrade, in an enamelled vessel provided with a stirring apparatus,
until a test portion, on being acidulated, no longer vields a considerable precipi-
tate of unchanged amido-naphthol sulphonic acid. The reaction mixture is then
rendered acid by adding a mineral acid in the manner described in the above
Example A, and filtered. The filtrate is further treated as described in the said
example, viz., it is mixed with an excess of caustic soda lye, and boiled in order
to remove the ammonia, then again rendered acid, and freed from the sulphurous
acid contained therein. From the so-obtained solution of alpha,-alpha-di-
hydroxy-naphthalene-alpha-sulphonic acid, this acid can be isolated in the usual
manner.
The acid thus produced exhibits the known properties.
EXAMPLE D.
PRODUCTION OF ALPHA-ALPHA-AMIDONAPHTHOL-ALPHA, MONOSULPHONIC ACID.
A mixture prepared from 25 parts of the sodium salt of alpha,-alpha-diamido-
naphthalene-alpha-monosulphonic acid, 50 parts of water, and 60 parts of a sodium
bisulphite solution, of 42 per cent. is heated for about 4 hours with con-
tinuous stirring, at about from 80 to 90 degrees Centigrade. The mixture is then
rendered alkaline by means of caustic soda-lye. and boiled until the develop-
ment of ammonia ceases. Subsequently the liquid is acidulated, the alpha,-
alpha-amido naphthol-alpha-monosulphonic acid being thus separated in the
shape of small white needles.
The process proceeds in an analogous manner if, instead of the alpha-naphthyl-
amine derivatives used in the above examples, other alpha-naphthylamine deriva-
tives are emploved, or if other salts of sulphurous acid, such as potassium bisul-
phite, or the like, are used.
My foreign correspondents wish to point out that they do not intend to con-
fine themselves to the particulars given in the above specification, as the examples
contained therein are merely typical, and can be varied within wide limits. Thus,
for instance, instead of heating the alphanaphthylamine derivatives with the
sulphurous acid, or its salts, in open vessels, this reaction can also be performed
in autoclaves.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me from abroad, I declare that what I claim is:
The process for the transformation of alpha-naphthylamine derivatives into

page_text: the corresponding alpha-naphthol derivatives, which process consists in treating
the alpha-naphthylamine derivatives with sulphurous acid, or with salts of this
acid, and subjecting the unstable intermediate products which are thus produced,
to the action of suitable agents, such as alkalies or the like, in order to trans-
form the same into the alpha naphthol derivatives, substantially as herein before
described.