Year: 1899

page_text: I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention (as communicated to me from abroad by
Actien-Gesellschaft für Anilin-Fabrikation, of Berlin, in the Empire of Germany,
Chemical Manufacturers) to be as follows:-
In the Specification No. 24527 of 1897 is described a process for the manufacture
of black disazo-colouring matters by combining the diazo-compounds of para-amido-
diphenylaminesulphonic acids with a-naphthylamine, again diazotising the amidoazo-
products thus obtained and finally coupling with naphtholsulphonic acids.
:
My correspondents have now found that colouring matters of similar character are
obtained by using as starting products such derivatives of para-amidodiphenylamine
as are substituted in the nucleus containing the diazotisable amido-group by a car-
boxyl-group COOH instead of a sulphonic-group SO₂H.
Such amidodiphenylaminecarboxylic acids are produced in a manner quite
analogous to the production of the corresponding sulphonic acids, namely by allowing
chloronitrobenzoic acid (COOH : Cl: NO₂- 1:2:5) to act on aromatic amines or
their sulphonic or carboxylic acids and subsequent reduction of the condensation
products thus obtained.
By condensing, for instance, the said chloronitrobenzoic acid with aniline, para-
nitrodiphenylaminecarboxylic acid is obtained. This acid forms needles of yellowish-
green colour which melt at 232° C., which are little soluble in water but more
soluble in diluted alcohol. By reducing this condensation product in the known
manner para-amidodiphenylaminecarboxylic acid is produced forming nearly
colourless needles melting at 228° C.
In the same manner other amido-compounds can be converted by condensation with
nitrochlorobenzoic acid and subsequent reduction into derivatives of para-amidodi-
phenylaminecarboxylic acid.
For instance, ortho-anisidine yields by this treatment para-amidomethoxyl-
diphenylaminecarboxylic acid which forms nearly colourless crystals melting at
231° C., if metanilic acid be used as starting product a sulphonic acid of
para-amidodiphenylaminecarboxylic acid, forming a nearly colourless powder, is
produced.
The production of the black colouring matters from these new derivatives as
primary compounds is effected in a manner quite analogous to that described in the
Specification No. 24527 of 1897 above mentioned. If for instance the diazo-com.

page_text: pound of para-amidodiphenylaminecarboxylic acid is combined with a-naphthyla-
mine, the intermediate product thus formed is diazotised again and the diazonzo-
compound thus produced is finally coupled with 8-naphtholdisulphonic acid Ra
valuable colouring matter is obtained dyeing wool in acid-bath dark black shades.
Dated this 27th day of March 1800
Manufacture of Black Disazo-Colouring Matters.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Buildings,
in the County of London, Consulting Engineer and Chartered Patent Agent, do
hereby declare the nature of this invention (as communicated to me from abroad by
Actien Gesellschaft für Anilin Fabrikation, of Berlin, in the Empire of Germany,
Chemical Manufacturers,) 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 No. 24527 of 1897 is described a process for the manufacture
of black disazo colouring matters by combining the diazo-compounds of para-amido-
diphenylaminesulphonic acids with a-naphthylamine again diazotising the amidoazo-
products thus obtained and finally coupling with naphtholsulphonic acids.
My correspondents have now found that colouring matters of similar character
are obtained by using as starting products such derivatives of para-amidodiphenyl-
amine as are substituted in the nucleus containing the diazotisable amido group by a
carboxyl-group COOH instead of a sulphonic-group SO H.
Such amidodiphenylaminecarboxylic acids are produced in a manner quite
analogous to the production of the corresponding sulphonic acids, namely by allowing
chloronitrobenzoic acid (COOH: C1: NO,= 1:2: 5) to act on aromatic amines or
their sulphonic or carboxylic acids and subsequent reduction of the condensation
products thus obtained.
By condensing for instance, the said chloronitrobenzoic acid with aniline para-
nitrodiphenylaminecarboxylic acid is obtained. This acid forins needles of yellowish-
green colour which melt at 232° C., which are little soluble in water but more
soluble in diluted alcohol. By reducing this condensation product in the known
manner para-amidodiphenylaminecarboxylic acid is produced forming nearly colour-
less needles melting at 228° C.
In the same manner other amido-compounds can be converted by condensation
with nitrochlorobenzoic acid and subsequent reduction into derivatives of para-amido-
diphenylaminecarboxylic acid.
For instance, ortho-anisidine yields by this treatment para-amidomethooxyl-
diphenylaminecarboxylic acid which forms nearly colourless crystals melting
at 231° C., if metanilic acid be used as starting product a sulphonic acid of para-
amidodiphenylaminecarboxylic acid, forining a nearly colourless powder, is produced.
The production of the black colouring matters from these new derivatives as
primary compounds is effected in a manner quite analogous to that described in the
Specification No. 24527 of 1897 above mentioned. If for instance the diazo-com-
pound of para-amidodiphenylaminecarboxylic acid is combined with a-naphthylamine,
the intermediate product thus formed is diazotised again and the diazoazo-compound
thus produced is finally coupled with 8-naphtholdisulphonic acid R a valuable
colouring matter is obtained dyeing wool in acid bath dark black shades.

page_text: Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described manufacture of black disazo-colouring matters by com-
bining the diazo-compounds of para-amidodiphenylaminecarboxylic acids or their
substitution products herein referred to with a-naphthylamine, diazotising again the
intermediate product thus obtained and finally coupling it with naphthols or
naphthol sulphonic acids.
2. The products manufactured as above set forth.