Improvements in Triphenylmethane Colouring Matters.
Year: 1891

page_text: Date of Application, 16th Jan., 1891
Complete Specification Left, 12th Oct., 1891-Accepted, 14th Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in Triphenylmethane Colouring Matters.
I, SYDNEY PITT of Sutton in the County of Surrey, Gentleman, (a communi-
cation to me from abroad by Leopold Cassella & Co. of Frankfort on Main in
the Empire of Germany, Chemists,) do hereby declare the nature of this invention
to be as follows:-
The object of this invention is the synthesis of colouring-matters belonging to
the group of triphenylmethane by a new method which consists in oxydizing
certain derivatives of diamidodiphenylmethane in the presence of monamines in
aqueous or alcoholic solution. This method is especially important for producing
sulphonated derivatives of secondary and tertiary rosanilines, dyeing violet and blue.
I. PRIMARY MATTERS.
Amongst the substituted products of diphenylmethane the following will give
the best results :
a.) Dimethyl (or ethyl) dibenzyldiamidodiphenylmethanedisulphonic acid
is prepared for example by heating in a water-bath 58 kilos. ethylbenzylaniline-
sulphonic acid together with a concentrated aqueous solution of 3 kilos. formicalde-
hyde. After 12 to 24 hours the reaction is terminated. The solution is rendered
alkaline with caustic soda and the sodium salt of the new acid precipitated with
common salt.
(In the following processes the acid need not be separated, the solution being
sufficiently pure for direct use.)
b.) Dimethyl (or ethyl) dibenzyldiamidodiphenylmethanemonosulphonic acid.
Dissolve 42 kilos. ethylbenzylaniline in 200 litres alcohol, add a concentrated
aqueous solution of 3 kilos. formicaldehyde and then 20 kilos. muriatic acid. Heat
for 10 hours at about 80° C. Pour the whole into water and separate the
colourless oil which is precipitated. This product is sulphurated by dissolving it
in 6 parts sulphuric acid and adding a small surplus of SO,. Take a sample and
if this is perfectly soluble in an alkali, pour the whole on to ice. The diethyl-
dibenzyldiamidodiphenylmethanemonosulphonic acid separates.
Tetramethyl (or tetracthyl) diamidetriphenylmethane.
The neanomation of these bodies is known
The preparation of these bodies is known
The amnines used up to the present are the following:
Aniline, o. toluidine, monomethyl (ethyl) aniline, dimethyl (ethyl) aniline,
benzyl-aniline-sulphonic acid, benzylmethyl (ethyl) anilinesulphonic acid, dibenzyl-
anilinesulphonic acid, phenylnaphtylamine, its sulphonated derivative, diphenylamine
and its homologues, methyldiphenylamine and its homologues, m. oxydiphenylamine
and its alkylated derivatives, m. oxydimethyl and diethyl-aniline.
II. COLOURING-MATTERS.
The colouring-matters are formed according to the general formula:
CH, (C¸HNX), + CH¸NY + 20 = HOC
+H₂O
\CH,NY

page_text: The method of working is illustrated by the following examples:
1.) 60 kilos. diethyldi benzyldiamidodiphenylmethanedisulphonic acid are dissolved
in 1000 litres of water. 12 kilos. dimethylaniline and then 20 kilos. bichromate of
potash are added. Heat for 25 hours at a temperature of 30°--40° C. The
chrome-hydrate is separated by filtration and out of the violet solution the
disulphonate of the diethyldimethyldibenzyltriamidotriphenylcarbinol is precipitated
with common salt.
2.) Mix together the solutions of 50 kilos. dimethyldi benzyldiamidodiphenyl-
methanmonosulphonic acid and 30 kilos. of the sodium salt of benzylethylaniline-
sulphonic acid. Add 20 kilos. bichromate of potash and either keep the
temperature at 40° C. for 24 hours, or boil during hour. The resulting violet
is easily soluble.
3.) Dissolve 25 kilos. tetramethyldiamidodiphenylmethane in muriatic acid con-
taining 7.3 kilos. HCl. After having added a solution of 29 kilos. ethylbenzyl-
anilinesulphonic acid, the mixture is oxidized by means of 20 kilos. bichromate of
potash. The reaction is terminated in 12 hours at a temperature of 60° C. The
free acid of the violet, slightly soluble in water, separates.
4.) Dissolve 60 kilos. diethyldibenzyldiamidodiphenylmethanedisulphonic acid in
the equivalent quantity of caustic soda. To the concentrated solution add 17 kilos.
diphenylamine dissolved in 100 kilos. alcohol and 22 kilos. muriatic acid (20° Bé.).
Oxidize this mixture with 20 kilos. bichromate of potash. Generally the reaction
will be terminated in 24 hours at a temperature of 40° C. Evaporate the alcohol,
filter and precipitate with common salt. The disulphonate of diethyldibenzyl-
phenyltriamidotriphenylcarbinol thus formed dyes wool a light reddish blue. If
instead of diphenylamine, the oxyethers of this base (which may be obtained for
example by alkylating metaoxydiphenylamine) are used, a dyestuff of a pure blue
shade is obtained. The homologues of diphenylamine and the corresponding
tertiary bases (methyldiphenylamine and the like) yield analogous products.
5.) Add the sodium salt of 180 kilos. m. oxydiphenylamine to the neutralized
solution of 60 kilos. diethyldibenzyldiamidodiphenylmethanedisulphonic acid in
1000 litres of water. Then add 20 kilos. bichromate of potash and 33 kilos.
muriatic acid. The solution is heated for 2 hours at 95° C. by a steam jet. Then
filter and precipitate the dyestuff with common salt. It dyes animal and vegetable
fibres a pure blue.
Instead of oxydiphenylamine, its homologues, its alkylated derivatives (which
are easily obtained by condensing resorcine with monoethylaniline &c.) and
m. oxydimethyl (diethyl) aniline may be used, without altering the result materially.
The chromic acid chosen as oxidizing agent in the foregoing examples, may of
course be replaced by other oxydants, such for example as peroxides and the salts
of oxide of copper.
It is not necessary to add the indicated quantity all at
once, it being possible, although less advantageous, to divide the reaction, by
forming successively the hydrole, the leuco-base and the carbinol. The formation
of the diphenylmethans and the oxidation may be effected in one operation. For
example one of the violets described may be obtained by mixing the solutions of
ethylbenzylanilinesulphonic acid (3 molecules) formic aldehyde (1 molecule) with
the oxidizing agent and heating this mixture for some time. The temperatures
and the concentration may also vary considerably.
Dated this 16th day of January 1891.
CARPMAEL & Co.,
Agents.

page_text: CH, (C,H,NX), + C,H,NY + 20
=
HOC
+ H₂O.
CH.NY

page_text: The method of working is illustrated by the following examples :
1.) 60 kilos. diethyldibenzyldiamidodiphenylmethanedisulphonic acid are dissolved
in 1000 litres of water. 12 kilos. dimethylaniline and then 20 kilos. bichromate of
potash are added and the whole heated during 25 hours at a temperature of
30°-40° C. The chrome-hydrate is separated by filtration and from the violet
solution the disulphonate of the diethyldimethyldibenzyltriamidotriphenylcarbinol
is precipitated with common salt.
2.) The solutions of 50 kilos. dimethyldibenzyldiamidodiphenylmethanemono-
sulphonic acid and 30 kilos. of the sodium salt of benzylethylanilinesulphonic acid
are mixed together, then 20 kilos. bichromate of potash are added, the temperature
is either kept at 40° C. for 24 hours or at the boil during hour. The resulting
violet is easily soluble.
3.) 25 kilos. tetramethyldiamidodiphenylmethane are dissolved in muriatic acid
containing 7-3 kilos. HCl. After having added a solution of 29 kilos. ethyl-
benzylanilinesulphonic acid, the mixture is oxidized by means of 20 kilos.
bichromate of potash. The reaction is terminated in 12 hours at a temperature
of 60° C. The free acid of the violet, slightly soluble in water, separates.
4.) 60 kilos. diethyldibenzyldiamidodiphenylmethanedisulphonic acid are dissolved
in the equivalent quantity of caustic soda. To the concentrated solution 17 kilos.
diphenylamine dissolved in 100 kilos. alcohol and 22 kilos. muriatic acid (20° Bé.)
are added and this mixture oxydized with 20 kilos. bichromate of potash.
Generally the reaction will be terminated in 24 hours at a temperature of 40° C.
After evaporation of the alcohol the mass is filtered and precipitated with common
salt. The disulphonate of diethyldibenzylphenyltriamidotriphenylcarbinol thus
formed dyes wool a light reddish blue. If instead of diphenylamine, the oxyethers
of this base (which may be obtained for example by alkylating metaoxydiphenyl-
amine) are used, a dyestuff of a pure blue shade is obtained. The corresponding
tertiary bases (methyldiphenylamine and the like) yield analogous products.
5.) The sodium salt of 18 kilos. metaoxydiphenylamine is added to the
neutralized solution of 60 kilos. diethyldibenzyldiamidodiphenylmethanedisulphonic
acid in 1000 litres of water. Then 20 kilos. bichromate of potash and 33 kilos.
muriatic acid are added. The solution is heated for 2 hours at 95° C. by a steam
jet. Then filtered and the dyestuff precipitated with common salt.
It dyes
animal and vegetable fibres a pure blue.
The chromic acid chosen as oxidizing agent in the foregoing examples, may of
course be replaced by other oxydants, for instance such as peroxides and the
salts of oxide of copper. It is not necessary to add the indicated quantity all at
once, it being possible, although less advantageous, to divide the reaction, by
forming successively the hydrole, the leuco-base and the carbinol. The formation
of the diphenylmethanes and the oxidation may be effected in one operation. For
example one of the violets described may be obtained by mixing the solutions of
ethylbenzylanilinesulphonic acid (3 molecules) formic aldehyde (1 molecule) with
the oxidizing agent and heating this mixture for some time. The temperatures
and the concentrations may also vary considerably.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1st. The process of producing violet or blue dyestuffs which consists. in the
simultaneous oxidation of derivatives of diamidodiphenylmethane and aromatic
monamines substantially as described.
2nd. The colouring matters which are obtained according to the process herein-
before described and claimed.
CARPMAEL & Co.,
Agents: