Improvements in the Manufacture of Colouring Matters.
Year: 1892

page_text: Date of Application, 21st Nov., 1892
Complete Specification Left, 17th Aug., 1893-Accepted, 23rd Sept., 1893
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Messrs. WIRTH & Co., of Frankfort-on-the-
Main, in the Empire of Germany, acting as Agents of A. Leonhardt & Co.,
of Mülheim, near Frankfort-on-the-Main, in the Empire of Germany,
Manufacturers.]
Improvements in the Manufacture of Colouring Matters.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
•
In the Specification of former Patent No. 1390 of 1892 I have shown that by
converting dimethylmetaamidocresol into its mononitroso derivative and by com-
bining this mononitroso derivative with naphthylamine or aromatic diamines blue
basic dyestuffs are obtained..
The communicators have since found, firstly, that instead of nitroso dimethyl-
metaamidocresol, nitrosodiethylmeta amidocresol can be used; secondly, that instead
of the nitroso derivatives, the corresponding azo derivatives may be employed, and
thirdly, that also the azo derivatives of dimethyl or diethylmetaamidophenol yield
such blue basic dyestuffs.
The above mentioned nitrosodiethylmetaamidocresol is obtained in a similar way
as its lower homologue, and the azo derivatives are obtained by combining diazo
bodies, for instance diazobenzol, with dialkylmetaamidophenol or cresol in an
alkaline or acetic acid solution; and the blue dyestuffs are formed by heating such
azo derivatives with an aromatic amine in a suitable dissolving or distributing agent
(for instance spirit or acetic acid)-preferably in the presence of mineralic acid.
Dated this 21st day of November 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Colouring Matters.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake, & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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:—
In the Specification of a former Patent No. 1390 the communicators have
shown that by converting dimethylmetaamidocresol into its mononitroso derivative
and by combining this mononitroso-derivative with alphanaphthylamine or with
aromatic diamines, blue basic dye-stuffs are obtained.
The said communicators have since found, firstly, that instead of nitrosodimethyl-
metaamidocresol, nitrosodiethylmetaamidocresol can be used; secondly, that instead
of the nitroso derivatives, the corresponding azo derivatives may be employed; and
thirdly, that also the azo-derivatives of dimethyl or diethylmetaamidophenol yield
such blue basic dye-stuffs.
First modification. When di-ethylmetaamidocresol of former Letters Patent
No. 20,25200 is treated with nitrous acid or with nitrite of sodium, in an acidulated
watery solution, it behaves in an analogous way to dimethylmeta amidocresol, viz.:
it is converted into dinitrosocresorcine, the mother liquid containing diethylamine,

page_text: When on the contrary chemically bound nitrous acid is employed, the result is
mononitrosodiethylmetaamidocresol. For the production of this mononitroso
compound it is most profitable to react with watery solutions of sodium nitrite on a
watery solution of a mineralic acid salt of diethylmetaanidocresol the employment
of alkylnitrites is less favourable because the so-formed products can only with
difficulty be obtained in a solid state. I therefore prefer to operate in the following
way:
To a solution of 7 kilos. of the chlorhydrate of diethylmetaamidocresol in
200 litres of water a watery solution of 3 kilos. of nitrite of sodium is gradually
added in the cold state and the liquid is allowed to stand for several days and is
stirred from time to time. The mononitrosodiethylmetaamidocresol separates
almost entirely in the form of a red crystalline precipitate, the rest is salted out.
It is soluble in dilute acids and in dilute caustic soda lye: when crystallized from
ligroine its melting point is at 77° C.
The production of blue basic colouring matters from this mononitroso derivative
is effected by heating a mineralic acid salt of nitrosodi-ethylmetaamidocresol with
an aromatic amine or a salt of such amine (employing about equal molecules of
both) in a suitable indifferent dissolving or distributing agent such as spirit or
methylic alcohol or acetic acid.
Amongst the aromatic amines I have tried the improved process especially with
the following alphanaphthylamine, ethylalphanaphthylamine, metaamidodimethyl-
uniline, metaamidodi-ethylaniline, metaamidodimethylparatoluidine, metaamidodi-
ethylparatoluidine, benzylmetaamidodimethylparatoluidine, paraphenylenediamine,
tetramethylmetaphenylenediamine.
EXAMPLE.
1st. 8 kilos. of the chlorhydrate of nitrosodiethylmetaamidocresol are heated with
4 kilos. of alphanaphthylamine and 40 litres of spirit at the reflux cooler until the
formation of colouring matter is finished. When cooling down the dye-stuff is
crystallized out and is filtered and pressed. It is easily soluble in water.
2nd. 53 kilos. of nitrosodiethylmetaamidocresol are heated with 3 kilos. of
metaamidodiethylparatoluidine, 30 litres of methylic alcohol and 2.5 litres of nitric
acid (of 40° B.) at the reflux cooler. After the reaction is finished, the whole mass
is diluted with hot water, the methylic alcohol is distilled over, impurities are
removed from the watery solution by means of acetate of sodium, and the dye stuff
is precipitated from the cooled and filtered liquid with common salt.
Second modification. As stated at the beginning of this Specification, blue basic
dye stuffs may also be obtained by condensing azo derivatives derived from dialkyl-
metaamidocresol. By experimenting in this way, I found that dimethylmetaamido-
cresol yields the best results, therefore this compound is especially hereinafter
mentioned.
The most simple azo dye stuff (which I employ by preference) is benzol-azo-
dimethyl-metaamidocresol. It may be produced by diazotizing aniline in the usual
manner and pouring the solution of diazobenzol obtained into an alkaline watery
solution of the sodium salt of dimethylmetaamidocresol. The combination is easily
effected in the cold state. By acidulating the product of the reaction, for instance,
with hydrochloric acid, the chlorhydrate of the azo dye stuffs is obtained.
The reaction between the azo compound and the aromatic amines takes place by
heating the two compounds in a suitable dissolving or distributing agent and in the
presence of some mineralic acid for a certain length of time; the reaction generally
requiring a longer time than by employing the nitroso derivatives, instead of the
azo compounds.
Amongst aromatic amines I have tried my process especially with the following:
Alphanaphthylamine, ethylalphanaphthylamine, metaamidodiethylaniline, meta-
amidodimethylparatoluidine, benzylmetaamidodimethylparatoluidine, tetramethyl-
metaphenylenediamine, paraphenylenediamine.
The purification of the colouring matters obtained is effected best by precipitating

page_text: the impurities from the watery solution of the raw product by means of carbonate
or acetate of sodium or the like; the pure colouring matter remaining in solution,
from which it is precipitated in the usual way.
EXAMPLES.
1st. 15 kilos. of the chlorhydrate of benzolazodimethylmetaamidocresol are heated
with 6 kilos. of alphanaphthylamine, 4 kilos. of hydrochloric acid (of 30° 。) and
40 litres of spirit, at the reflux cooler, during several hours. The mass finally
assumes an intensely blue colour, and when cooled down, the dye stuff is crystallized
out and is filtered off the mother lƑe.
2nd. 15 kilos. of the chlorhydrate of benzol-azo-dimethylmetaamidocresol are
heated with 5 kilos. of tetramethylmetaphenylenediamine and 50 litres of spirit, at
the reflux cooler. When the mass has finally assumed a greenish tint and when a
sample, by diluting with hot water, shows the formation of the blue colouring matter,
the whole is extracted with hot water, the solution is purified with acetate of sodium
and the dye-stuff is precipitated from the filtered and cooled liquid by means of
chloride of zinc and common salt.
3rd. 15 kilos. of the chlorhydrate of benzolazodimethylmetaamidocresol are
heated with 5 kilos. of paraphenylenediamine, 5 litres of hydrochloric acid (of 30%)
and 40 litres of glacial acetic acid, for several hours at the reflux cooler. The
solution is coloured successively a brownish, then a greenish and finally a bluish
tint. The whole mass is then extracted with boiling water, the solution is purified
with acetate of sodium and the dye-stuff is precipitated from the solution.
Third modification. In order to produce benzolazodimethylmetaamidophenol or
benzolazodiethylmetaamidophenol (these being the most simple azo derivatives
belonging to this class) the watery solutions of molecular quantities of the chlor-
hydrates of diazobenzol and of dialkylmetaamidophenol are mixed in the cold state
and the formation of the azo-colour is effected by successively adding a solution of
acetate of sodium.
The formation of basic blue colouring matters from these azo-derivatives is quite
analogous to the one described in the second part of this Specification. Generally
the azo-dye-stuffs derived from diethylmetaamidophenol will render larger quantities
of blue colouring matter than those derived from the methyl compounds. Amongst
aromatic diamines, the following are employed by preference: metaamidodimethyl-
aniline, metaamidodiethylaniline, metaamidodimethylorthotoluidine, metaamido-
dimethylparatoluidine, metaanidodiethylparatoluidine benzylmetaamidodimethyl-
paratoluidine, paraphenylenediamine, tetramethylmetaphenylenediamine.
As an example, I heat 15 kilos. of benzolazodiethylmetaamidophenol with 5 kilos.
of tetramethylmetaphenylenediamine, 10 litres of hydrochloric acid (30%) and
50 litres of spirit, until the mass has assumed greenish blue colour. It is then
diluted with about 200 litres of hot water, impurities are removed from the solution
by the addition of about 10 kilos. of acetate of sodium, and the pure colouring
matter is precipitated from the cooled and filtered liquid by means of chloride of
zinc and commou salt.
As another example, I heat 15 kilos. of benzolazodimethylmetaamidophenol with
5 kilos. of metaamidoimethylparatoluidine, 5 litres of hydrochloric acid (of 30%),
and 50 litres of spirit, until the liquid has assumed a blue colour. After cooling,
the colouring matter is partly crystallized out, the rest being isolated in the same
way as indicated before.
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 by my
foreign correspondents, I declare that what I claim is :-
1. The production of mononitrosodiethylmetaamidocresol by the herein-described
process which consists in reacting with metallic nitrites on the acid salts of

page_text: diethylmetaamidocresol in the absence of any further mineralic acid, substantially
as hereinbefore described.
2. Mononitrosodiethylmetaamidocresol prepared substantially as hereinbefore
described.
3. The production of blue basic colouring matters by the action of mononitrosodi-
ethylmetaamidocresol on alphanaphthylamine or aromatic diamines or their sub-
stitutes, especially on. those pointed out in the first part of this Specification all
substantially as hereinbefore described.
4. The blue basic colouring matters prepared according to the process claimed in
the third claiming clause.
5. The production of blue basic colouring matters by the action of azo-derivatives
from dimethylmetaamidocresol, and especially of benzol-azo-dimethylmetaamido-
cresol, on alphanaphthylamine or aromatic diamines or their substitutes, especially
on those pointed out in the second part of this Specification all substantially as
hereinbefore described.
6. The blue basic colouring matters prepared according to the process claimed
in the 5th claiming clause.
7. The production of blue basic colouring matters by the action of azo derivatives
from dimethylmetaamidophenol or diethylmetaamidophenol, and especially of
benzolazodimethylmetaamidophenol and benzolazodiethylmetaamidophenol, on
aromatic diamines or their substitutes, especially on those pointed out in the third
part of this Specification, all substantially as hereinbefore described.
8. The blue basic colouring matters prepared according to the process claimed
in the 7th ola
oluiming clause.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.