Manufacture of New Amido Bases and of Azo Colouring Matters therefrom.
Year: 1894

page_text: Date of Application, 12th Mar., 1894-Accepted, 28th Apr., 1894
CUMPLEIE DI MUITIVATION
Manufacture of New Amido Bases and of Azo Colouring Matters
therefrom.
I, Dr. RICHARD KOREFF, of Pelc Tyrolka near Prague, Bobemia, Austria,
Chemist, 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 :-
The reaction of formaldehyde upon anilin, o-toluidine, a naphthylamine, benzidine,
tolidine and dianisidine, has already been investigated by various persons such as
Tollens, Schiff, Pulvermacher, Durand and Huguenin. In all such investigations
it was observed that the formaldehyde always condensed with the particular amine
in such manner that it takes either two hydrogen atoms from one amido group, or
one bydrogen atom from each of two amido groups, for condensation, yielding
bodies which have either no basic properties, or are secondary amines.
An apparent exception is made by the bases discovered by Durand, which he
obtained by condensation of formaldehyde with benzidine, tolidine and dianisidine,
and which contain free amido groups.
But also in this case the condensation took place in such manner that only a
part of the amido groups were substituted, while amido groups in excess remained
unaffected.
I have discovered that formaldehyde is capable of condensing with the said
amines in such manner as to leave the amido groups intact if the condensation be
effected in concentrated sulphuric acid.
By this means, new primary amines are obtained which are of particular
interest on account of their being capable of producing valuable new azo colouring
matters.
EXAMPLE I.
21.4 kilos. o-toluidine are dissolved in 100 kilos. sulphuric acid of 66° Bé., and are
gradually mixed with 7.5 kilos. formaldehyde of 40 per cent.
The mixture is stirred for some time until the condensation of the formaldehyde
with the toluidine has taken place, which is effected in a short space of time. The
mass is poured into water and the solution is rendered alkaline, when the new
compound is deposited as a yellowish precipitate.
Any rests of o-toluidine that may not have entered into the reaction are driven
off by means of steam. The new base remains in the form of an oil.
It is allowed to coagulate, after which it is filtered washed and pressed, whereby
the condensation product is obtained of the requisite purity. The new base
dissolves easily in acids or alcohol and the mineral acid solutions give with nitrite
readily and smoothly diazo bodies. The nitrite thus consumed shows accurately
that no substitution of the amido groups has taken place.
The new base is essentially characterised by its melting point, which is
about 60° C., and its incapacity for crystallisation.
The diazo compound prepared from the base gives, with phenoles, amines, and
their sulpho acids, colouring matters that dye wool in an acid bath, and that are
favourably distinguished from the corresponding o-toluidine colours by their bluer
tints and slower development.
EXAMPLE II

page_text: sulphuric acid, and are condensed with 7.5 kilos. formaldehyde of 40 p.c. the
operation being effected rapidly and smoothly.
The mass is poured into water, the sulphate of the new base remaining in
solution; the solution is rendered alkaline and the new base is separated by
filtration. After separation it appears аз a grey-white body that melts at
about 60° C. and is soluble with difficulty in alcohol and ether, whereby it is easily
possible to remove the last remaining particles of a naphthylamine.
The base is easily dissolved in dilute sulphuric acid or hydrochloric acid, and
gives with nitrite an easily soluble diazo compound, which forms with amines,
phenoles, and their sulpho acids, new azo colouring matters that equalise well.
42°4 kilos. o-tolidine are dissolved in 400 kilos. concentrated sulphuric acid and
7.5 kilos. of 40 p.c. formaldehyde are stirred into the cooled solution.
The smell of formaldehyde disappears by degrees and the end of the con-
densation process is recognisable by the fact that on dropping a sample into water
the crystalline separation of the, with difficulty soluble, tolidine sulphate no longer
takes place.
The mass is now poured into 2500 litres of cold water, and if the reaction has
been conducted correctly, a clear yellow solution will be obtained of which a
measured quantity, when determined by nitrite, will accurately agree with the
quantity of tolidine employed, which proves that no reaction of the formaldehyde
upon the amido groups has taken place.
I have succeeded in finding in this acid solution two isomeric bases which can be
readily separated on account of their essentially different degrees of solubility, as
the one base gives a sulphate that dissolves with great difficulty in water or
slightly acidulated water, while the second base gives very easily soluble salts.
If now the acid solution of the two bases, as obtained by pouring the original
reaction mass into water, has an alkali carefully added to it, the more or less
insoluble sulphate of the one base (base S) will be entirely precipitated before the
acid solution has become perfectly neutral, while the filtrate contains the sulphate
of the second base (base L) in solution, this being only precipitated from the
solution when this has become alkaline.
The new bases are easily distinguishable from o-tolidine, for whereas the latter
is soluble with difficulty in hydrochloric acid of about 10 p.c. and is practically
insoluble in dilute sulphuric acid and oxalic acid, all the salts of the new bases
are formed already in the cold, and to a great extent dissolve completely on being
slightly heated.
The base S gives a neutral sulphate soluble with difficulty in water, which
however, unlike tolidine is easily soluble in dilute sulphuric acid.
The melting
point of the new bases, which are always obtained in an amorphous condition is
about 60° C., while that of the easily crystallisable tolidine is exactly 130° C.
The new bases are also different from that of Durand as shewn by the following
.constitution formulæ of the two:
--Dנת

page_text: The tetrazo compounds of the new bases are very readily soluble, and are
precipitated from their solutions by means of alkalies in the form of easily filtered
white flocky substances. The new bases are tolerably easily soluble in ether.
have combined the bases with the following amines and phenoles, and have obtained
Lable colouring matters:
I
ve combined the bases with the Ionowiug un
erefrom valuable colouring matters :
With two molecules of:
Salicylic acid
Naphthionic acid
1-5 naphthylamine sulpho acid
Brönners acid (ẞ naphthylamine-ẞ sulpho acid)
ẞ naphthylamine-8 sulpho acid
1-4 naphthol sulpho acid
-
With one molecule of naphthionic acid and one molecule
of 14 naphthol sulpho acid
With two molecules of y amido-naphthol-sulpho acid
(alkaline)
With one molecule of y amido-naphthol sulpho acid
(acid) and one molecule of salicylic acid
One molecule of a naphthylamine farther diazotised and
combined with 1.4 naphthol sulpho acid
yellow
red
red
red
red
blue violet
claret
black
red
blue black.
Generally speaking, these colouring matters are similar in their properties to-
those prepared from tolidine; the tints of the former are however somewhat
yellower, without being inferior to the latter as regards brightness.
For the preparation of the tetrazo colouring matters, the following examples may
serve:
1. 21.8 kilos. of the base are dissolved in 55 kilos. hydrochloric acid of 33 p.c..
and a sufficient quantity of water; to the cooled solution 13-8 kilos. of nitrite are
then added, and the tetrazo body thus formed is poured into a solution of 70 kilos.
naphthionate of soda with 42 kilos. of acetate of soda. An insoluble intermediate
product is at once formed, which, after stirring for some time is transformed into
the colouring matter.
The mass is then boiled, rendered alkaline, filtered, and dried.
The new colouring matter is a brown red powder, very easily soluble in water.
and dyes cotton in an alkaline bath a fine scarlet red.
2. If the tetrazo body prepared as in example (1) is poured into a solution of
33-5 kilos. of naphthionate of soda and 16 kilos. of carbonate of soda, there will be
at once formed the insoluble intermediate product, 35 kilos. of a naphthol sulphonate-
of soda 14 are then added, and the mass is stirred for some time until the formation
of the colouring matter is completed. Care has then to be taken that the compound.
always remains alkaline.
The further treatment is then effected in the same way as in (1).
claret red.
EXAMPLE IV.
if
The condensation of o-dianisidine is effected as easily as with o-tolidine;
548-8 kilos. o-dianisidine are dissolved in concentrated sulphuric acid, and there
is added the calculated quantity of formaldehyde (in the present case 7.5 kilos..
of a 40 p.c. material) and after the smell of formaldehyde has disappeared the mass
is treated as with tolidin; there will, also in this case be obtained a base
which contains the amido groups intact, and which can be readily distinguished from.
0 o-dianisidine.
The azo colouring matters obtained therefrom readily dye cotton in an alkaline-
hath and are distinguishable from the colouring matters from o-dianisidine by their-

page_text: For the production of these azo colouring matters the following will serve as an
example:
25 kilos. of the base are dissolved in 55 kilos. of hydrochloric acid and water, and
the cooled solution is diazotised with 13.8 kilos. of nitrite. The finished tetrazo
body is allowed to flow into 50 kilos. of a 1-4 naphthol sulphonate solution, which
is kept alkaline to the end.
After a short time the colouring matter is formed and is worked in the known
manner. It dyes cotton blue.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. A manufacture of new bases by the condensation of o-toluidine, a naphthyl-
amine o-tolidine, o-dianisidine, with formaldehyde in concentrated sulphuric acid
solution, substantially as described.
2. A manufacture of new azo colouring matters from the bases referred to in the
first claim, substantially as described.
D
1
حيمد
1
1 1001
ABEL & IMRAY,
Agents for the Applicant.