Method for the Preparation of Azo- and Azoxy-aldehydes.
Year: 1898

page_text: Date of Application, 18th Jan., 1898
Complete Specification Left, 15th Oct., 1898-Accepted, 7th Jan., 1899
PROVISIONAL SPECIFICATION.
Method for the Preparation of Azo- and Azoxy-aldehydes.
i
.1.
We, ARTHUR GEORGE GREEN, F.L.C., F.C.S., of 13, Kings Drive, Heaton Moor,
near Stockport, and ALEXANDER MEYENBERG, Ph.D., of 13, Nelson Street, Plymouth
Grove, Manchester, both Chemists to the Clayton Aniline Company Limited, of
Clayton, Manchester, do hereby declare the nature of this invention to be as
follows:-
1. "
This invention relates to a process for the preparation of azo- and azoxy-compounds
containing aldehyde groups. In the Specification of an Application for a German
Patent F9906 a process is described by P. Friedländer for obtaining paranitrobenzalde-
hyde orthosulphonic acid by oxidation with permanganates of the colouring matters
(curcumine, etc.,) obtained by alkaline condensation of paranitrotoluolsulphonic acid.
We have found that by employing only so much permanganate as will at once be
taken up, and decolourised, a new aldehyde is obtained which is probably an azoxy-
benzaldehydesulphonic acid, or azoxy-benzaldehyde carboxysulphonic acid. The new
aldehyde, like the nitrobenzaldehyde sulphonic acid, is an easily soluble and nearly
colourless substance but it differs from the nitrobenzaldehyde sulphonic acid in the
following particulars: (a) It is readily precipitated from its aqueous solution by salt.
(b) It is taken up by wool from a boiling acid bath and the colourless wool can be
subsequently developed to a deep orange-brown by immersion in a dilute acetic acid
solution of phenylhydrazine. (c) Its phenylhydrazide is darker in colour than that
of nitrobenzaldehydesulphonic acid and the solution thereof in concentrated sulphuric
acid is a bluish-green colour instead of a brownish-yellow colour.
We have already shewn by our application for Letters Patent No. 21825 of 1897
that by the oxidation of dinitrostilbene disulphonic acid with potassium permanganate
paranitrobenzaldehydeorthosulphonic acid is produced, and a further study of these
reactions has shewn that the conversion of stilbene derivatives into the corresponding
aldehyde compounds by oxidation with permanganates in cold dilute aqueous
solution is a general reaction applicable to all stilbene colouring matters.
This reaction is represented by the following general equations:-
1
2 R.N.CH(SU₂H) CHU
In all cases the first attack of the perinanganate appears to be upon the stilbene
group which is thereby converted into two aldehyde groups, the molecule being split
up into two. Further action of the permanganate leads to oxidation of the aldehyde
groups and may also attack the azoxy or other groups which are present. In certain
cases where easily oxidisable amido or hydroxy groups are present these may be
oxidised concomitantly, with the stilbene group and thus render impossible the
Sealation of Bure product

page_text: To obtain the best results the operation should be performed in dilute solution at
a low temperature and care should be taken that the addition of permanganate is
not continued beyond the point at which rapid decolourisation ceases to take place.
The general method of procedure is illustrated by the following examples. The parts
are by weight.
PREPARATION OF AN AZO ALDEHYDE FROM CHRYSOPHENINE.
65 parts of commercial chrysophenine free from salt are dissolved in 4000 parts of
water. Into the solution cooled to 0° to 5° Centigrade is slowly run with rapid
agitation a cold solution of 21 parts of potassium permanganate in 400 parts of
water. When the oxidation is complete the mixture is warmed to coagulate the
manganese dioxide, filtered therefrom and the azoaldehyde, or mixture of azoalde-
hydes, is salted out from the filtrate, separated and dried.
red.
The product is a light yellow powder which is somewhat sparingly soluble in water
the solution being also light yellow. The solution in concentrated sulphuric acid is
With phenylhydrazine acetate the aqueous solution yields an orange precipitate
of the phenylhydrazide. It dyes wool from an acid bath a light yellow shade which,
on immersion in a weak bath of phenylhydrazine acetate, changes to orange.
formation is probably represented by the following equation :-
Its
PREPARATION OF AN AZOALDEHYDE FROM HESSIAN YELLOW.
If, in the foregoing example, the chrysophenine be replaced by 70 parts of
commercial Hessian yellow freed from salt a product is obtained having properties
very similar to those of the product of that example. Its formation is probably
represented by the equation:
50 parts of commercial Mikado orange 3RO, washed free from salt, are dissolved
in 1300 parts of hot water, cooled to 0-5° Centigrade and oxidised with 24 parts of
potassium permanganate dissolved in 600 parts of water. The filtrate after warming
and separating the oxide of manganese is acidified with acetic acid and concentrated
by evaporation until, on cooling, the azoaldehyde crystallises out. The latter forms
a brownish crystalline powder easily soluble in water which with phenylhydrazine yields
a reddish-brown precipitate. It dyes wool from an acid bath a pale yellow, which,
on development with phenylhydrazine, becomes a brownish-red. It probably has a
constitution represented by the formula:
CHO.CH,(SO,H).N..CH (SOH).CHO
If, in the above example, the Mikado orange, be replaced by equivalent quantities
of other colouring-matters of the same group such as curcumine S, direct yellow G,
Mikado golden yellow or by the aldehyde colouring matters resulting from the
hydrolysis of the colouring matters claimed under Letters Patent No. 12922 of 1896

page_text: similar products are obtained. These all possess the remarkable property of being
directly fixed by wool from an acid bath whilst the wool is either not coloured at all
thereby, or only a pale yellow, but upon subsequent treatment with a solution of
phenylhydrazine deep orange-brown to brownish-red shades are developed.
Dated thin 10th day of T1002
We, ARTHUR GEORGE GREEN, F.I.C., F.C.S., of 13, Kings Drive, Heaton Moor,
near. Stockport, and ALEXANDER MEYENBERG, Ph.D. of 13, Nelson Street, Plymouth
Grove, Manchester, both Chemists to the Clayton Aniline Company Limited, of
Clayton, Manchester, 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 :-
This invention relates to a process for the preparation of azo and azoxy compounds
containing aldehyde groups. In the Specification of an Application for a German
Patent F9906 a process is described by P. Friedländer for obtaining paranitro-
benzaldehyde-orthosulphonic acid by oxidation with permanganates of the colouring
matters (curcumine, etc.) obtained by alkaline condensation of paranitro-toluol-
sulphonic acid. We have found that by einploying only so much permanganate as
will at once be taken up and decolourised, a new aldehyde is obtained which is
probably an azoxy-benzaldehydesulphonic acid or azoxy-benzaldehyde-carboxy-
sulphonic acid. The new aldehyde, like the nitrobenzaldehyde-sulphonic acid, is an
easily soluble and nearly colourless substance, but it differs from the nitrobenzalde-
hyde sulphonic acid in the following particulars :-
:-
(a.) It is readily precipitated from its aqueous solution by salt. (b.) It is taken
up by wool from a boiling acid bath and the colourless wool can be subsequently
developed to a deep orange-brown by immersion in a dilute acetic acid solution of
phenylhydrazine. (c.) Its phenylhydrazide is darker in colour than that of nitro-
benzaldehyde-sulphonic acid and the solution thereof in concentrated sulphuric acid
is a bluish-green colour instead of a brownish-yellow colour.
We have already shewn by our application for Letters Patent No. 21825 of 1897
that by the oxidation of dinitrostilbenedisulphonic acid with potassium permanganate-
paranitrobenzaldehydeort hosulphonic acid is produced, and a further study of these
reactions has shewn that the conversion of stilbene derivatives into the corresponding
aldehyde compounds by oxidation with permanganates in cold dilute aqueous solution
is a general reaction applicable to all stilbene colouring matters.
This reaction is represented by the following general equations:-
In all cases the first attack of the permanganate appears to be upon the stilbene
group which is thereby converted into two aldehyde groups, the molecule being split
up into two. Further action of the permanganate leads to oxidation of the aldehyde
groups and may also attack the azoxy or other groups which are present. In certain

page_text: 1
cases where easily oxidisable amido, or hydroxy, groups are present these may be
oxidised concomitantly with the stilbene group and thus render impossible the
isolation of.a pure product.
To obtain the best results the operation should be performed in dilute solution at a
low temperature and care should be taken that the addition of permanganate'is not
continued beyond the point at which rapid decolourisation ceases to take place. The
general method of procedure is illustrated by the following examples. The parts are
by weight.
PREPARATION OF AN AZOALDEHYDE FROM CHRYSOPHENINE.
65 parts of commercial chrysophenine free from salt, are dissolved in 4000 parts of
water. Into the solution cooled to 0° to 5° Centigrade is slowly run with rapid
agitation a cold solution of 20 parts of potassium-permanganate in 400 parts of
water. When the oxidation is complete the mixture is warmned to coagulate the
manganese-dioxide, filtered therefrom and the azoaldehyde, or mixture of azo-
aldehydes, is salted out from the filtrate, separated and dried. The product is a
light yellow powder which is somewhat sparingly soluble in water the solution being
also light yellow. The solution in concentrated sulphuric acid is red. With phenyl-
hydrazine-acetate the aqueous solution yields an orange precipitate of the phenyl-
hydrazide. It dyes wool from an acid bath a light yellow shade which, on immersion
in a weak bath of phenyl-hydrazine-acetate, changes to orange. Its formation is
probably represented by the following equation:-
If, in the foregoing example, the chrysophenine be replaced by 70 parts of com-
mercial Hessian-yellow freed from salt a product is obtained having properties very 2
similar to those of the product of that example. Its formation is probably repre-
sented by the equation:-
CH.CH,(SO'H).N₂.C₂H₂(OH) CO₂H
2 CHO.CH,(SO,H).N..CH(OH)CO H.
PREPARATION OF AN AZOALDEHYDE FROM MIKADO-ORANGE.
50 parts of commercial Mikado-orange 3 RO, washed free from salt, are dissolved
in 1300 parts of hot water, cooled to 0° -5° Centigrade and oxidised with 24 parts
of potassium-permanganate dissolved in 600 parts of water. The filtrate after warming
and separating the oxide of manganese is acidified with acetic acid and concentrated
by evaporation until, on cooling, the azoaldehyde crystallises out. The latter forms a
brownish crystalline powder easily soluble in water which with phenylhydrazine yields
a reddish brown precipitate. It dyes wool from an acid bath a pale yellow, which, on
development with phenylhydrazine, becomes a brownish-red. It probably has a con-
stitution represented by the formula :-

page_text: If, in the above example, the Mikado-orange be replaced by equivalent quantities
of other colouring matters of the same group such as circumine S, direct yellow G,
Mikado-golden-yellow or by the aldehyde colouring matters resulting from the
hydrolysis of the colouring matters claimed under Letters Patent No. 12922 of 1896
similar products are obtained. These all possess the remarkable property of being
directly fixed by wool from an acid bath whilst the wool is either not coloured at all
thereby, or only a pale yellow, but upon subsequent treatinent with a solution of
phenylhydrazine deep-orange brown to brownish-red shades are developed.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The preparation of azoxy and azo aldehydes by oxidation of colouring-matters of
the stilbene series with a permanganate in cold dilute aqueous solution, substantially
as described.
2. As new products the azoxy or azo aldehydes obtained by oxidation of
curcumine S, Mikado-yellow, direct-yellow G, Mikado-orange, Mikado-golden-
yellow, Hessian-yellow, chrysophenine, and other colouring matters of the stilbene
series.
Dated this 15th day of Ontabos 1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.