Improvements in the Manufacture and Production of Colouring Matters.
Year: 1898

page_text: Date of Application, 28th Jan., 1898
Complete Specification Left, 15th Oct., 1898-Accepted, 14th Jan., 1899
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture and Production of Colouring
Matters.
We, ARTHUR GEORGE GREEN, F.I.C., F.C.S., of 13, Kings Drive, Heaton Moor,
near Stockport, in the County of Lancaster, and RENE LÉVY, of 124, Church
Street, Bradford, Manchester, in the said County, both Chemists to The Clayton
Aniline Company Limited, of Clayton, near Manchester aforesaid, do hereby
declare the nature of this invention to be as follows:-.
By condensation of paranitrobenzaldehydeortho sulphonic acid CH (CHO)
(SOH) (NO₂) [1:2:4] with secondary and tertiary aromatic amines, or their
sulphonic acids nitro leuco compounds of blueish-green colouring-matters are
obtained which are fast to alkalies.
The present invention relates to the substitution of the nitro group in the
above nitro-leuco-compounds by the amido (NH), hydroxy (OH) alkyloxy (OR)
or chloro (Cl) groups by which means leuco compounds of bluer colouring-matters
are obtained some of which are of very pure shade. With the exception of the
hydroxy compounds (which are reddened by alkalies) all the colouring matters
obtained from these leuco compounds possess a remarkable stability against the
action of alkalies due to the ortho position of the sulphonic acid group in respect
to the central methane carbon.
For the preparation of the amido-leuco compounds the following methods can
be employed.
a. Reduction of the nitro leuco-compounds.
b. Condensation of paraamidobenzaldehyde-ortho sulphonic acid with secondary
and tertiary amines or their sulphonic acids.
The hydroxy-leuco compounds can be obtained by either of the following
methods.
a. From the above amido leuco compounds by diazotisation and boiling with
water.
b. By condensation of parahydroxybenzaldehyde ortho sulphonic acid with
secondary and tertiary amines and their sulphonic acids.
The alkyloxy leuco-compounds are obtained by alkylation of the hydroxy-
leuco-compounds.
For the preparation of the chloro-leuco compounds the following methods can
be employed:
:
a. From the above amido leuco compounds by decomposition of the diazo-
chloride with cuprous chloride or copper powder.
b. By condensation of parachlorobenzaldehyde-orthosulphonic acid
secondary and tertiary amines or their sulphonic acids.
with
The conversion of the leuco compounds into colouring matters can be effected
by oxidation with ferric chloride, potassium bichromate, manganese dioxide or
lead peroxide, preferably with the latter.
When the leuco compounds contain only one sulphonic group they can be

page_text: ted with advantage to further sulphonation by treatment with ordinary
or fuming sulphuric acid.
PREPARATION OF AMIDO-LEUCO COMPOUNDS.
Method A. The reduction of the nitro-leuco compounds can be effected by
means of zinc dust by boiling with neutral sodium sulphite, sodium bisulphite
or by other means. The method is illustrated by the following examples:
1. Trimethylsulphobenzyldiamidoparanitro orthosulphotriphenylmethane ob-
tained by condensing paranitrobenzaldehyde orthosulphonic acid with one mole-
cular proportion of dimethyl-aniline and one molecular proportion of methyl
benzylaniline sulphonic acid is dissolved in water and reduced with zinc dust
and acetic acid. When the reduction is complete the solution of the amido-leuco
compound is filtered. On oxidation it gives a colouring matter which can be
salted out and dyes wool a reddish-blue fast against the action of alkalies.
with
2. 24 parts by weight of tetramethyldiamido paranitrosulphotriphenylmethane
obtained by condensing paranitrobenzaldehyde ortho sulphonic acid
two molecular proportions of dimethylaniline arc boiled with 100 parts by volume
of a 20% solution of bisulphite of soda. The nitro leuco-compound gradually
dissolves as the reduction proceeds. When all the nitro leuco compound is
dissolved the solution is acidified. with sulphuric acid and the excess of sulphurous
acid is evaporated off. On oxidation it gives a colouring-matter which dyes
wool a reddish-blue very fast against the action of alkalies.
Method B. The para amidobenzaldehyde orthosulphonic acid is obtained by
reduction of paranitrobenzaldehyde orthosulphonic acid preferably by boiling with
sodium bisulphite. The condensation with the secondary or tertiary, amine
can be effected by boiling together in acid solution. The method is illustrated by
the following example.
400 parts. by volume of an 8 per cent. solution of para-nitrobenzaldehyde-
orthosulphonic acid are boiled for two hours with a solution of 190 parts. by
weight of sodium metabisulphite. The solution is then acidified with 135 parts
by weight of concentrated sulphuric acid and boiled. till the excess of sulphurous
acid is expelled. The solution of the paraamidobenzaldehyde-orthosulphonic acid
thus obtained, is diluted to 400 parts by volume and boiled for 15 hours with
40 parts by weight of dimethylaniline. After neutralising with sodium carbonate
and boiling off the excess of unaltered dimethyl-aniline, the amido-leuco-com-
pound separates as a viscid mass which on cooling, solidifies to a semi-crystalline
solid.
If, in the foregoing example, the dimethylaniline be replaced by 85 parts of
sodium ethylbenzylaniline sulphonate a leuco compound is obtained which is
casily soluble in water, and. on oxidation yields a colouring-matter which
dyes wool from an acid bath a reddish blue, fast against the action of alkalies.
PREPARATION OF HYDROXY- AND ALKYLOXY-LEUCO COMPOUNDS.
The conversion of the amido leuco compounds into hydroxy leuco compounds
takes place readily by diazotisation and boiling. The hydroxy leuco compounds
can also be prepared by condensation of secondary or tertiary amines with para
hydroxy-benzaldehyde orthosulphonic acid, which latter is obtained from the
above described para amido-benzaldehyde orthosulphonic acid by diazotisation and
boiling with water.
The oxyleuco compounds, on oxidation, give rise to blue colouring matters
which on account of the replaceable hydrogen of the hydroxy group are changed
in colour (reddened) by alkalies. This disadvantage is overcome by alkylation of
the hydroxy group which is effected by means of alkyl haloids or alkyl sulphates.
Example: 112 parts by weight of the above described amido leuco-compound
obtained by condensing para-amido-benzaldehyde ortho sulphonic acid with
dimethylaniline or by reduction of tetramethyl diamido paranitro sulpho
triphenyl-methane are dissolved in 500 parts, by volume, of water and 15 parts
by volume of hydrochloric acid (33%). The solution is cooled to 0° Centigrade

page_text: and diazotised by the addition of 18 parts by volume of a 10% solution of sodium
nitrite. After 1 hour the solution is heated to boiling until the evolution of
nitrogen ceases. After neutralising with sodium carbonate and cooling the greater
part of the hydroxy leuco-compound separates out and the remainder is precipitated
by the addition of salt.
PREPARATION OF CHLORO LEUCO COMPOUNDS.
The conversion of the amido leuco-compounds into chloro leuco-compounds is
readily effected by the action of copper or cuprous chloride on the diazo chlorides
according to the methods of Sandmeyer or Gatterman. The chloro-leuco-com-
pounds can also be prepared by replacing in the same manner the amido group
of para-amido benzaldehyde ortho sulphonic acid by chlorine and then condens-
ing the parachlorobenzaldehyde orthosulphonic acid thus obtained with secondary
and tertiary amines and their sulphonic acids. On oxidation the chloro leuco-
compounds give rise to colouring-matters which are distinguished by a pure bright
blue shade and great fastness against the action of alkalies.
Example: 112 parts by weight of the aforesaid amido-leuco compound: obtained
by condensing para amido benzaldehyde ortho sulphonic acid with dimethylaniline
or by reduction of tetramethyldiamidoparanitrosulphotriphenylmethane are dis-
solved in 30 parts by volume of water and 40 parts by volume of hydrochloric
acid (33%). The solution is then cooled to 0° Centigrade and diazotised by
the addition of 18 parts by volume of a 10% solution of sodium nitrite. When
the diazotisation is complete copper paste equal to one part of copper, is slowly
added. After the evolution of nitrogen has ceased the solution is filtered, diluted
with water freed from copper by the addition of ammonium sulphide, and filtered
hot. On neutralising the filtrate the chloro leuco compound separates as a light
coloured precipitate.
On oxidation with lead peroxide the leuco compound gives a blue colouring
matter which dyes wool and silk very pure bright blue shades.
1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in the Manufacture and Production of Colouring
Matters.
We, ARTHUR GEORGE GREEN, F.I.C., F.C.S., of 13, Kings Drive, Heaton Moor,
near Stockport, in the County of Lancaster, and RENE LÉVY, of 124, Church
Street, Bradford, Manchester, in the said County, both Chemists to The Clayton
Aniline Company Limited, of Clayton, near Manchester aforesaid, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
_
By condensation of paranitrobenzaldehyde ortho sulphonic acid CH, (CHO)
(SO,H) (NO) [1:2:4] with secondary or tertiary aromatic amines, or their
sulphonic acids nitro leuco compounds of blueish-green colouring-matters are
obtained which are fast to alkalies.
The present invention relates to the substitution of the nitro group in the
above nitro-leuco-compounds by the amido (NH₂), hydroxy (OH) alkyloxy (OR)
or chloro (Cl) groups whereby leuco compounds are obtained which by oxidation
are converted into colouring-matters of bluer, and in some cases of purer, shade.

page_text: With the exception of the hydroxy compounds (which are reddened by alkalies)
all the colouring matters thus obtained possess a remarkable degree of stability
against the action of alkalies due to the ortho position of the sulphonic acid
group in respect to the central methane carbon.
For the preparation of the amido-leuco compounds the following methods can
be employed.
a. Keduction of the nitro leuco-compounds.
b. Condensation of para amidobenzaldehyde-orthosulphonic acid with secondary,
or tertiary, amines, or sulphonic acids thereof.
The hydroxy-leuco compounds can be obtained by either of the following
methods.
A. From the above amido leuco compounds by diazotisation and boiling with
water.
B. By condensation of parahydroxybenzaldehyde-ortho-sulphonic acid with
secondary or tertiary amines or sulphonic acids thereof.
The alkyloxy leuco-compounds are obtained by alkylation of the hydroxy-
leuco-compounds.
For the preparation of the chloro-leuco-compounds the following methods can
be employed;
A. From the above amido leuco compounds by decomposition of the diazo-
chloride with cuprous chloride or copper powder.
B. By condensation of parachlorobenzaldehyde-orthosulphonic acid
secondary or tertiary amines or sulphonic acids thereof.
with
The conversion of the leuco-compounds into colouring-matters by oxidation can be
effected by means of ferrie-chloride, potassium bichromate, manganese dioxide
potassium permanganate, or lead peroxide, preferably with the latter.
When the leuco compounds contain only one sulphonic group they can be
submitted with advantage, to further sulphonation by treatment with ordinary
or fuming sulphuric acid.
1.
PREPARATION OF AMIDO-LEUCO COMPOUNDS.
-
Method A. The reduction of the nitro-leuco compounds can be effected by
means of zinc dust, by boiling with neutral sodium sulphite, sodium bisulphite,
or by other means. The method is illustrated by the following examples ;-
Trimethylsulphobenzyldiamidoparanitro-orthosulphotriphenylmethane, ob-
tained by condensing paranitrobenzaldehyde ortho-sulphonic acid with one mole-
cular proportion of dimethyl-aniline and one molecular proportion of methyl-
benzylaniline sulphonic acid, is dissolved in water and reduced by means of zinc dust
and acetic acid. When the reduction is complete the solution of the amido-leuco-
compound is filtered. On oxidation it gives a colouring matter which can be
salted out. It dyes wool a reddish-blue fast against the action of alkalies.
2. Twenty-four parts, by weight, of tetramethyldiamido-paranitrosulphotriphenyl-
methane, obtained by condensing para-nitrobenzaldehyde-ortho-sulphonic acid with
two molecular proportions of dimethyl-aniline, are boiled with 100 parts by volume
of a 20 per cent. solution of bisulphite of soda. The nitro-leuco-compound gradually
dissolves as the reduction proceeds. When all the nitro-leuco compound is
dissolved the solution is acidified, by means of sulphuric acid, and the excess of sul-
phurous acid is evaporated off. On oxidation it gives a colouring matter which dyes
wool a reddish-blue very fast against the action of alkalies.
Method B. The para-amidobenzaldehyde orthosulphonic acid can be obtained by
reduction of paranitrobenzaldehyde orthosulphonic acid by boiling with
sodium bisulphite. The condensation with the secondary, or tertiary, amine,
can be effected by boiling the para-amidobenzaldehyde ortho sulphonic acid
and the amine together in acid solution. This method is illustrated by the
following example.
400 parts, by volume, of an 8 per cent. solution of para-nitrobenzaldehyde-
orthosulphonic acid are boiled, for two hours, with a solution of 190 parts, by

page_text: weight, of sodium metabisulphite. The solution is then acidified with 135 parts
by weight of concentrated sulphuric acid, and boiled, till the excess of sulphurous
acid is expelled. The solution of the para-amidobenzaldehyde-orthosulphonic acid
thus obtained, is diluted to 400 parts by volume and boiled for 15 hours with
40 parts by weight of dimethyl-aniline. After neutralising with sodium carbonate
and boiling off the excess of unaltered dimethylaniline, the amido-leuco-com-
pound separates as a viscid mass which, on cooling, solidifies to a semi-crystalline
solid.
If, in the foregoing example, the dimethyl-aniline be replaced by 85 parts of
sodium ethylbenzylaniline-sulphonate a leuco compound is obtained which is
easily soluble in water, and, which on oxidation, yields a colouring-matter which
dyes wool, from an acid bath, a reddish-blue, fast against the action of alkalies.
PREPARATION OF HYDROXY- AND ALKYLOXY-LEUCO COMPOUNDS.
The conversion of the amido leuco compounds into hydroxy leuco compounds
takes place readily by diazotisation and boiling. The hydroxy leuco compounds
can also be prepared by condensation of a secondary, or tertiary, amine with para-
hydroxybenzaldehyde orthosulphonic acid, which latter is obtained from the
above described para amidobenzaldehyde orthosulphonic acid by diazotisation and
boiling with water.
The hydroxyleuco compounds, on oxidation, give rise to blue colouring matters
which on account of the replaceable hydrogen of the hydroxy group are changed
in colour (reddened) by alkalies. This disadvantage is overcome by alkylation of
the hydroxy group which is effected by means of alkyl haloids or alkyl sulphates.
Example: 112 parts by weight of the above described amido leuco-compound
obtained by condensing para-amido-benzaldehyde-ortho-sulphonic acid with
dimethylaniline, or by reduction of tetramethyldiamido-paranitrosulpho-
triphenylmethane, are dissolved in 500 parts, by volume, of water and 15 parts,
by volume, of hydrochloric acid (33%). The solution is cooled to 0° Centigrade
and diazotised by the addition of 18 parts by volume of a 10% solution of sodium
nitrite. After 1 hour the solution is heated to boiling until the evolution of
nitrogen ceases. After neutralising by means of sodium carbonate and cooling the
greater part of the hydroxy-leuco-compound separates out and the remainder is
precipitated by the addition of salt.
PREPARATION OF CHLORO-LEUCO-COMPOUNDS.
The conversion of the amido-leuco-compounds into chloro-leuco-compounds is
readily effected by the action of copper, or cuprous chloride, on the diazo-chlorides
according to the methods of Sandmeyer, or Gatterman. The chloro-leuco com-
pounds can also be prepared by replacing, in the same manner, the amido group
of para amido-benzaldehyde-orthosulphonic-acid by chlorine and then condens
ing the parachlorobenzaldehyde-orthosulphonic-acid thus obtained with dimethyl-
aniline diethylaniline, monoethylorthotoluidine benzylethylaniline benzylmethyl-
aniline benzylorthotoluidine or sulphonic acids the last three bases. On oxidation
the chloro-leuco-compounds give rise to colouring-matters which are distinguished
by a pure bright blue shade and great fastness against the action of alkalies.
Example: 112 parts by weight of the aforesaid amido-leuco compound obtained
by condensing para-amido-benzaldehyde-ortho-sulphonic acid with dimethylaniline,
or by reduction of tetramethyldiamido-paranitrosulphotriphenylmethane, are dis-
solved in 30 parts, by volume, of water and 40 parts, by volume, of hydrochloric
acid (33%). The solution is then cooled to 0° Centigrade and diazotised by
the addition of 18 parts by volume of a 10% solution of sodium nitrite. When
the diazotisation is complete copper paste, equal to one part by weight of copper, is
slowly added. After the evolution of nitrogen has ceased the solution is filtered.
diluted with water freed from copper by the addition of ammonium sulphide, and
filtered hot. On neutralising the filtrate the chloro-leuco compound separates as
a light coloured precipitate.

page_text: On oxidation with lead peroxide the leuco compounds yields a blue colouring-
matter which dyes wool and silk very pure bright blue shades.
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 production of blue to bluish-green colouring-matters of the triphenyl-
methane series which are characterised by containing an alkyloxy, amido, or
halogen group in the para position, and a sulphonic group in the ortho position
of the nonquinonoid nucleus, substantially according to the methods described.
2. The production of blue colouring-matters of the triphenylmethane series-
(a) From the para nitroleuco compounds by replacement of the nitro group
by chlorine and subsequent oxidation.
(b) By condensing parachlorobenzaldehyde-orthosulphonic acid with dimethyl-
aniline, diethylaniline, monoethylorthotoluidine, benzyl-ethylaniline,
benzylmethylaniline, benzylorthotoluidine, or sulphonic acids of the
last three bases, and subsequent oxidation of the leuco compound
obtained, substantially as described.
3. The production of parachlorobenzaldehyde-orthosulphonic acid by replacing
the amido group in para-amidobenzaldehyde-ortho-sulphonic acid by chlorine by
means of the diazo reaction.
D
171 1
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.