Improvement in the Manufacture of Colouring Matters.
Year: 1892

page_text: Date of Application, 23rd Jan., 1892
Complete Specification Left, 14th Oct., 1892-Accepted, 26th Nov., 1892
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 and Co., of
Muhlheim, near Frankfort-on-the-Main, in the Empire of Germany, Manu-
facturers.]
Improvement 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:-
It has been found that dialkylmetaamidocresol produced from dialkylorthotoluidinę
behaves in various ways when treated with free nitrous acid or with nitrites.
Thus for instance when a watery solution of nitrite of sodium is gradually added
to a watery solution of dimethylmetaamidocresol with hydrochloric acid in excess,
a substance is obtained which is recognised as being dinitrosocresorcine, and in the
molten liquor is found a certain quantity of dimethylamine divided off from the
molecule of dimethylamidocresol. On the other hand when alkylnitrites react on
dimethylmetaamidocresol, or its salts, or a watery solution of nitrite of sodium is
added to a watery solution of the hydrochlorate of dimethylmetaamidocresol in the
absence of further hydrochloric acid (with or without the presence of a metallic
salt, such as chloride of zinc) another substance is obtained which is found to be the
mononitroso-derivative of dimethylmetaamidocresol, which up to the present was not
obtainable.
It has further been found that dinitrosocresorcine as mentioned above is not
proper raw material for producing artificial dye-stuffs, whilst the mononitroso-
derivative of dialkylmetaamidocresol can easily be condensed with aromatic amines
(especially with naphthylamines or aromatic metadiamines or their substitutes) in
presence of some mineral acid yielding very fast and beautiful new blue basic
coloring matters which differ from those produced from mononitrosodialkylmeta-
amidophenol and which easily dye fast on mordanted cotton.
The manufacture of these new coloring matters is effected in the usual way by
heating the two relative components in the presence of some mineral acid prefer-
ably with some dissolving or distributing agent such as spirit or acetic acid or the
like.
Dated this 23rd day of January 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvement 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:-
Dimethylmetaamidocresol as claimed in the Specification of former Letters
Patent 2025200 when subjected to a nitrosation behaves in various ways, according
to the mode of operation employed. By treating it with nitrous acid or with nitrite
of sodium in an acidulated watery solution (which is the most common way in
n

page_text: practice) a brownish crystalline precipitate gradually separates from the liquid
having only acid properties dissolving in alkalies.
The chemical nature of this substance has been found by an investigation of the
mother-lyes of the brown precipitate in which dimethylamine was. discovered.
From this discovery it seemed obvious that the brown substance was a derivative
of cresorcine, and when the dinitroso derivative of cresorcine was produced it was
found that it was in fact identical with the above mentioned brownish precipitate.
It therefore follows that the reaction between nitrous acid and dimethylmetaamido-
cresol takes place in the following manner :-
с.н. (сн.
+2HNO,=CH (CH)‹
\(NO),
+NH(CH,),+HẠO
\N (CH₂)₂
This dinitrosocresorcine has not been found capable of forming dyestuffs in
combination with aromatic amines. The results however are quite different if
chemically bound nitrous acid be employed either in the form of nitrites of alkyls
(such as ethyl or amyl) or by acting with metallic nitrites upon an acid salt of
dimethylmetaamidocresol in the absence of further mineralic acid. In all such
cases a product is obtained which is quite different from the above mentioned
dinitrosocresorcine. Thus for instance when alcoholic cold solutions of the sodium
salt of dimethylmetaamidocresol and amylnitrite are mixed the liquid gradually
becomes of a yellowish brown tint, and after standing some time in the cold bright
leaves of a brownish black colour are separated. These crystals represent a sodium
salt. They dissolve easily in cold water. The yellowish red solution when treated
with acetic acid allows a red precipitate to separate which is soluble in mineralic
acids, and when hydrochloric acid in a concentrated watery solution is employed the
red precipitate is transformed into yellow crystals of a chlorhydrate.
By mixing cold acqueous solutions of the chlorhydrate of dimethylmetaamido-
cresol and nitrite of sodium (employing about equal molecules of both) no reaction
is at first observed, but gradually the liquid becomes of a brownish red colour and
a dark red precipitate separates, identical to that which is obtained by treating the
solution of the above-mentioned sodium salt with acetic acid.
The nitrosoderivative produced in such a way has been found to be mononitroso-
dimethylmetaamidocresol for the production of which many unsuccessful attempts
have been made and which is now produced for the first time. When it is crystal-
lized out of toluol its melting point is at 105° C. It is capable of forming salts
both with acids and with alkalies. When reaction takes place with this nitroso-
derivative on aromatic amines under proper circumstances a new series of blue
basic colouring matters is obtained. Amongst aromatic amines mention may be
made especially of alphanaphthylamine or aromatic diamines and the present
process has been especially tried by employing the following amines.
Alphanaphthylamine, ethylalphanaphthylamine, dimethylalphanaphthylamine,
diethylalphanaphthylamine, benzylalphanaphthylamine, metaamidodimethylaniline,
ethylmetaamidodimethylaniline metaamidodimethylparatoluidine, ethylmetaamido-
dimethylparatoluidine, benzylmetaamidodimethylparatoluidine, metaamidodiethyl-
paratoluidine, dibenzylmetatoluylenediamine tetramethylmetaphenylenediamine,
tetramethylmetatoluylenediamine, paraphenylenediamine, paraamidodimethyl-
aniline paratoluylenediamine, 1-4 naphthylenediamine.
The production of the new colouring matter is best effected by employing about
equal molecules of a mineralic salt of nitrosodimethylmetaamidocresol and of the
aromatic amine and heating the two components in a suitable dissolving or distri-
buting agent, such as spirit or methylic alcohol or acetic acid.

page_text: muriatic acid of 30% HCl and the whole mass is then heated in a water bath
until the colour is fully developed. After cooling down the dyestuff is crystallized
out of the fluid, filtered, pressed and dried.
Second. 13 kilos. of benzylmetaamidodimethylparatoluidine 11 kilos. of the
chlorhydrate of nitrosodimethylmetaamidocresol and 90 litres of spirit are heated
until the reaction is finished and the nitrosocompound has disappeared. The
product is then diluted with hot water, 20 kilos. of acetate of sodium are added in
order to remove impurities the liquid is filtered after cooling down and the colouring
matter is precipitated from the filtered liquid with common salt and chloride of
zinc.
Third. 6 kilos. of paraphenylenediamine, 17 kilos. of the chlorhydrate of nitroso-
dimethylmetaamidocresol and 50 litres of glacial acetic acid are heated in a
water bath until the formation of colouring matter is finished. The colouring
matter is separated from the product of the reaction in a similar way to that
indicated in the 2nd example.
Having now particularly described and ascertained the nature of this invention
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 mononitrosodimethylmetaamidocresol or its salts by the
herein described process which consists in reacting with nitrous acid either in form
of ethylnitrite or amylnitrite on dimethylmetaamidocresol or its salts, or in the
form of metallic nitrites on the acid salts of dimethylmetaamidocresol in the
absence of further mineralic acid, substantially as hereinbefore described.
Mononitrosodimethylmetaamidocresol prepared substantially as hereinbefore
2.
described.
3. The production of blue basic colouring matters by the action of mononitroso-
dimethylmetaamidocresol on alphanaphthylamine or aromatic diamines or their
substitutes, especially on those pointed out in the Specification all substantially as
herein before described.
4. The blue basic colouring matters prepared according to the process claimed
in the third claiming clause.
the third claiming clause.
Babad
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.