Improvements in and relating to the Manufacture and Production of Diphenylnaphthylmethane Dyes.
Year: 1892

page_text: Date of Application, 21st Nov., 1892
Complete Specification Left, 21st Aug., 1893-Accepted, 21st Oct., 1893
PROVISIONAL SPECIFICATION.
[Communicated from abroad by THE FARBENFABRIKEN vormals FRIEDRICH
BAYER & Co., of Elberfeld, in the Empire of Germany.]
Improvements in and relating to the Manufacture and Production of
Diphenylnaphthylmethane Dyes.
I HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:-
My foreign correspondents have described in the Specification of my application
for Letters Patent No. 14728, dated 15th August 1892, a series of triphenyl-
methane dye stuffs and diphenylnaphthylmethane dye stuffs, which are obtained
from alkylised diamidobenzhydrols and certain dibenzylamido sulpho acids of the
benzene series, or certain phenylnaphthylamine sulpho acids, tolylnaphthylamine
sulpho acids, and analogues thereof.
My foreign correspondents have further described in the Specification of my
application for Letters Patent No. 19246, dated 26 October 1892, that the leuco
products resulting from alkylised diamidobenzhydrols and phenylnaphthylamine
sulpho acids, tolylnaphthylamine sulpho acids, or analogues thereof, can be
converted more advantageously into dye stuffs, if they are previously treated
with sulphonating agents, and the so-formed leuco poly sulpho compounds are
oxidised.
The satisfactory oxidation which takes place in the latter case, seems to be
caused, as already mentioned in the last named Specification, by a separation of
water from the leuco compounds, due to the presence of sulphonating agents, the
action consisting in the combination of the hydrogen atom of the amido group
with the hydroxylic group of the sulpho group, and in the splitting of the so-
formed water. Sulpho amido compounds are thus produced, which are readily
oxidised, as they do not contain a free hydrogen atom in the amido group.
My foreign correspondents have further found, that leuco products and dye
stuffs which are analogous to the leuco compounds and coloring matters described
in the Specification of the aforesaid. two Applications, can be produced by
combining alkylised diamidobenzhydrols, in general, with naphthylamine sulpho
acids, or substituted naphthylamine sulpho acids, and either directly oxidising the
thus formed leuco products, or previously sulphonating the resulting leuco
compounds, and subsequently oxidising the leuco polysulpho products thus
obtained.
By "naphthylamine sulpho acids, or substituted naphthylamine sulpho acids,"
my foreign correspondents understand the following products, viz. :—
(1.) Alphanaphthylamine monosulpho acids, alphanaphthylaminepolysulpho
acids, betanaphthylaminemonosulpho acids, betanaphthylamine polysulpho acids,
and substitution products of all these acids containing the substituents in the
naphthaline nucleus.
(2.) Monoalkylnaphthylamine sulpho acids, and dialkylnaphthylamine sulpho
acids, which are obtained by heating alpha- or betanaphthylaminemonosulpho
acids or polysulpho acids, with one molecule or with two molecules of halogen
alkyls, alkyl sulphates, or the like alkyl salts derived from fatty alkyls (such as
methyl, ethyl, and the like), from aromatic alkyl (such as phenyl, tolyl, and the
like from benzyl and similar alkvla

page_text: (3.) Dinaphthylaminemonosulpho acids and dinaphthylaminepolysulpho acids.
My foreign correspondents have in general prepared the last named dinaphthyl-
amine sulpho acids by heating naphthylamine sulpho acids with naphthylamines.
Alphadinaphthylaminemono- and poly sulpho acids are also obtained, if alpha-
naphthylamine mono- and poly sulpho acids are heated with alphanaphthylamine,
whilst alphanaphthylaminemono- and- polysulpho acids are converted by heating
with betanaphthylamine, into alphabetadinaphthylaminemono- and polysulpho
acids, which contain the sulpho groups in the alpha naphthyl radicle. Beta-
naphthylaminemono- and- polysulpho acids, when heated with alphanaphthylamine,
yield in an analogous manner alphabetadinaphthylaminemono- and polysulpho
acids, containing the sulpho groups in the beta naphthyl nucleus. The analogous
betadinaphthylaminemono- and poly-sulpho acids are obtained by heating beta-
naphthylaminemono- and polysulpho acids with betanaphthylamine.
In order to illustrate the method of producing these dinaphthylamine sulpho
acids, the following example is given, the parts being by weight :-
PRODUCTION OF ALPHADINAPHTHYLAMINEMONOSULPHO
NAPHTHYLAMINE ΜΟΝΟ SULPHO
AMINE.
ACID FROM ALPHA-
ACID (14) AND ALPHANAPHTHYL-
10 parts by weight of. dried and finely pulverised alphanaphthionic acid
(NH, SO,H= 1:4) are heated with 40 parts of alphanaphthylamine, to
from 150 to 180 degrees centigrade, taking care, by continual stirring, that the
naphthionic acid is thoroughly mixed with alphanaphthylamine, which is in a
molten state. After about 6 hours, the formation of alphadinaphthylamine mono
sulpho acid (alphanaphthyl-alphanaphthionic acid) is completed. The resulting
mass is then boiled with water, and after neutralising with ammonia liquid, the
watery liquid is decanted from the alphanaphthylamine employed in excess, and
from the dinaphthylamine, which is produced as by-product. Out of the solution
thus obtained, when cold, the ammonium salt of alphadinaphthylamine monosulpho
acid (alphanaphthylaphanaphthionic acid) separates in crystallised form, viz., as
white tablets, whilst the ammonium salt of alphanaphthionic acid remains dissolved
in the mother liquid, and can be separated therefrom. The alphadinaphthylamine-
mono sulpho acid (alphanaphthylalphanaphthionic acid) is isolated in free state
from the above ammonium salt by means of the known methods.
In a similar manner, the other alphadinaphthylamine sulpho acids are obtained,
if, in the above example, in place of alphanaphthionic acid, the isomeric alpha-
naphthylamine sulpho acids, or the corresponding quantities of naphthylamine
di-sulpho acids, or other alphanaphthylamine poly sulpho acids, are employed, viz.,
heated with alphanaphthylamine.
If the alpbanaphthylamine is replaced by beta naphthylamine, alphabetadi
naphthylamine sulpho acids result, which contain the sulpho groups in the alpha-
naphthyl nucleus.
The process is effected in a similar manner, if betanaphthylamine mono- or- poly
sulpho acids are heated with alphanaphthylamine. In this case, alphabeta-
dinaphthylaminesulpho acids are formed, which contain the sulpho group in the
beta naphthyl nucleus.
The analogous betabetadinaphthylamine sulpho acids are formed in the same
manner, viz., by heating betanaphthylamine mono or polysulpho acids with beta-
naphthylamine.
The dinaphthylamine sulpho acids hereinbefore specified are soluble in water
with difficulty, or even partially insoluble, whilst the alkaline salts derived there-
from readily dissolve in water, and can be salted out by adding common salt to
their solutions in water.
My foreign correspondents have described, in the foregoing first example, one

page_text: nethod of producing alphanaphthylaphanaphthionic acid, which is an alpha-
dinaphthylamine monosulpho acid. The process sketched therein can, in general,
be employed for producing the other dinaphthylamine sulpho acids. My foreign
correspondents, however, do not limit themselves to the above proportions, which
may be varied. For instance, the quantity of alphanaphthylamine employed
may be increased or diminished, within certain limits; the temperature can be
raised or lowered, and correspondingly, the time of reaction may be shortened or
lengthened, and likewise the isolation of the dinaphthylamine sulpho acid, and its
separation from alphanaphthylamine employed in excess, and from dinaphthylamine,
generally formed as by product, can be otherwise effected.
I will now describe the production of the leuco compounds and dyestuffs derived
from dinaphthylamine sulpho acids hereinbefore specified, and the naphthylamine
sulpho acids, substituted naphthylamine sulpho acids (which contain the
substituents in the naphthalene nucleus), monoalkyl and dialkylnaphthylamine
sulpho acids above mentioned.
The process for obtaining these leuco products and dyestuffs, in general, is
analogous to that which my foreign correspondents have described in the Specifica-
tion of application for Letters Patent No. 14728 dated 15th August 1892. The
first produced leuco derivatives resulting from alkylised diamidobenzhydrols and
the sulpho acids hereinbefore specified, can be previously subjected to a treatment
with sulphonating agents, according to the process described in the Specification of
my application for Letters Patent No. 19246, dated 26th October 1892, and the
sulphonated leuco products thus obtained can be more effectively oxidised.
The process for producing leuco compounds and dye stuffs from alkylised diamido
benzhydrols and naphthylamine sulpho acids, is illustrated by the following second
example. The parts are by weight :-
PRODUCTION OF A LEUCO PRODUCT AND
DYE STUFF FROM TETRAMETHYL-
DIAMIDOBENZHYDROL AND ALPHANAPHTHYLAMINE ORTHO-MONO-SULPHO
ACID.
4.5 parts of alphanaphthylamine ortho-mono-sulpho acid are added to 5'4 parts
of tetramethyldiamido benzhydrol dissolved in 40 parts of sulphuric acid (con-
taining 10 per cent. of pure acid). The resulting liquid is heated for 2 hours
at 80 degrees centigrade. On cooling, the liquid becomes solid, and the leuco
product is isolated by pressing the resulting mass and drying the residue thus
obtained.
If the leuco compound is dissolved in acetic acid, and then oxidised by means of
the calculated quantity of lead dioxide, a dye stuff results which produces on wool
violet-blue shades. It dissolves in water only with difficulty.
By heating the above leuco product in a solution of dimethylaniline with zine
chloride, at a temperature from 130 to 150 degrees centigrade, distilling off again
the dimethylaniline employed, dissolving the residue in acetic acid, and oxidising
the same in the known manner by means of lead dioxide, a dye stuff is obtained
which possesses no acid properties, but is of basic nature, and produces, for instance,
on cotton prepared with tannic acid, or the like, bluish violet shades. It is evident,
that in this reaction, viz., on heating the said leuco compound with zinc chloride,
a formation of anhydride between the sulpho and amido group takes place.
An analogous formation of anhydride, viz., the production of a sulpho amido
compound takes place, if the above leuco derivative is treated with sulphonating
agents.
The process of treating with sulphonating agents the first produced leuco
compound, and subsequently oxidising the so-formed leuco poly sulpho compound,
is described in the following third example, which is typical of the process of
manufacture of leuco poly sulpho compounds from alkylised diamidobenzhydrols

page_text: CONVERSION OF THE LEUCO PRODUCT OBTAINED AS DESCRIBED IN THE
PRECEDING SECOND EXAMPLE, INTO A SO-CALLED LEUCO POLY SULPHO
COMPOUND, AND OXIDATION OF THE LATTER INTO THE DYESTUFF.
4.75 parts of the leuco compound obtained as described in the foregoing second
example, are dissolved in 23.5 parts of fuming sulphuric acid (containing
25 per cent. of anhydride), and the resulting liquid is heated for about 10 hours
at 25 degrees centigrade.
The so-formed mass is poured into ice water, and after neutralising with lime and
filtering off the calcium sulphate, the filtrate is evaporated. In this manner, the
calcium salt of the leuco poly sulpho acid results. The latter also contains a
sulpho amido group, like the analogous leuco poly sulpho compounds described
in the Specification of my application for Letters Patent No. 19246, dated
26th October 1892.
The oxidation of the so-formed leuco polysulpho compound is effected with
great ease, by dissolving the said calcium salt in about 4 times its weight of acetic
acid (containing 50 per cent. of pure acid), and oxidising by means of 4 parts of
a lead dioxide paste containing 60 per cent. of lead dioxide. The so-formed dye-
stuff is (after salting out, pressing, and drying) a brown powder which easily
dissolves in water, and produces on wool, intense bluish violet shades, which are
fast against the action.of alkalies.
In an analogous manner as described in the foregoing second and third examples,
the leuco products, sulphonated leuco products, and the dye stuffs derived from
these leuco products and sulphonated leuco products, are obtained, if, in place of
alphanaphthylamine ortho mono sulpho acid, the isomeric alphanaphthylamine
mono sulpho acids, or betanaphthylamine sulpho acids, or the corresponding quantities
of alpha and beta naphthylamine poly sulpho acids are employed, or if tetramethyl
diamido benzhydrol is replaced by analogous alkylised diamido benzhydrols.
The processes described in the aforegoing second and third examples will also
serve, if, in place of naphthylamine sulpho acids, substituted naphthylamine sulpho
acids, which contain the substituents in the naphthalene nucleus, or if, in place of
naphthylamine sulpho acids, mono and dialkylnaphthylamine sulpho acids, for
instance, monomethyl-dimethyl, monoethyl diethyl, monobenzyl, dibenzylnaphthyl-
amine sulpho acids, or analogues and homologues thereof, are employed.
Of course, the methods illustrated by the preceeding second and third examples
can be varied. For instance, in the foregoing second example, the free alpha-
naphthylamineorthomonosulpho acid can be replaced by the corresponding
quantities of alkaline salts thereof, the temperature may be raised or lowered, and
correspondingly the time of reaction can be shortened or extended, the isolation of
the leuco product can be effected in another manner, and the oxidation can be
carried out by means of the methods generally employed for such purposes.
The process of sulphonation described in the preceding third example, and that
of analogous leuco products herein before specified, can be effected by means of
other sulphonating agents, and the isolation of the resulting leuco poly sulpho
compounds can be carried out by means of the methods known in chemistry for
analogous purposes.
The manufacture of leuco compounds & dyestuffs from alkylised diamidobenz-
hydrols, and the dinaphthylamine sulpho acids herein before specified, is effected in
an analogous manner to that described in the above second example, and the first
produced leuco compounds can either be oxidised directly, or treated previously
with sulphonating agents, & the resulting leuco-poly-sulpho compounds then
oxidised.
:.
::.

page_text: compounds, and dyestuff's therefrom, obtained by means of dinaphthylamine
sulpho acids, the following Examples IV, V, and VI are given.
Fourth ExampLE.
FROM
PRODUCTION OF THE LEUCO COMPOUND
HYDROL AND
TETRAMETHYLDIAMIDOBENZ-
ACID (ALPHADI-
ALPHANAPHTHYLALPHANAPHTHIONIC
NAPHTHYLAMINE SULPHO ACID).
13 parts (by weight) of the ammonium salt of alphanaphthylalphanaphthionic
acid and 9-45 parts of tetramethyldiamidobenzhydrol (the latter being dissolved in
100 parts of water and 75 parts of sulphuric acid, at 66 degrees Baumé) are heated
in the water bath.
The condensation commences at 80 degrees centigrade. By neutralizing with
sodium carbonate, the leuco product is separated as a resinous mass, which soon
becomes solid. The latter easily dissolves in a boiling diluted solution of sodium
carbonate, and out of this solution, when cold, the sodium salt of the leuco
compound separates in crystallised form, viz., in scales, with mother-of-pearl like
lustre.
CONVERSION. OF
THE
FIFTH EXAMPLE.
LEUCO
PRODUCT (OBTAINED ACCORDING
TO
THE
FOURTH EXAMPLE) INTO THE LEUCO POLY SULPHO COMPOUND.
1 part by weight of the leuco product, obtained as described in the foregoing
fourth example, is introduced into about 5 parts by weight of fuming sulphuric
acid (containing 25 per cent. of anhydride), and the resulting liquid mixture is
allowed to stand for 10 hours, at from 20 to 30 degrees centigrade. If the
mixture is heated to from 50 to 60 degrees centigrade, the sulphonation will be
completed in a shorter time.
The sulphonation being complete, the mixture is poured into ice water.
Lime
is added until the liquid shews a neutral re-action, and the calcium sulphate thus
formed is filtered off.
The resulting filtrate is evaporated, and in this manner the calcium salt of the
leuco poly-sulpho acid is obtained, but the said filtrate may also be used directly
for producing the dye stuff by an oxidation process.
1
PRECEDING
SIXTH EXAMPLE.
OXIDATION OF THE LEUCO PRODUCT (OBTAINED AS DESCRIBED IN THE
FOURTH EXAMPLE), AND OF THE SULPHONATED LEUCO
COMPOUND (OBTAINED AS DESCRIBED IN THE LAST FIFTH EXAMPLE)
INTO THE CORRESPONDING DYE-STUFFS.
A solution, in water, containing either 17.5 parts, by weight, of the sodium salt
of the said leuco product (obtained as described in the fourth example), or 20 parts,
by weight, of the calcium salt of the sulphonated leuco compound (obtained as
described in the foregoing fifth example), is mixed with 40 parts, by weight, of
acetic acid (containing 50 per cent. of pure acid), and 80 parts, by weight, of water;
11 parts, by weight of a lead dioxide paste containing 60 per cent. of lead dioxide
are then added, in order to effect the oxidation.
The resulting dye stuffs, which are isolated in the usual manner, produce, on
wool, blue shades possessing great fastness against the action of alkalies.
The colouring matter obtained from the sulphonated leuco compound dissolves in
water with greater ease than that resulting from the leuco product of the fifth
example, which is a leuco mono sulpho acid, and possesses an equalizing property
when used in dyeing with other colouring matters.
.The methods described in the foregoing Examples IV, V, and VI, for producing
Leuco products, sulphonated leuco compounds, and dye stuffs therefrom, by means of

page_text: tetramethyldiamidobenzhydrol and alpha dinaphthylamine sulpho acid, also can
be employed for producing the analogous leuco products and dye stuffs from
alkylised diamido benzhydrols, and the dinaphthylamine sulpho acids hereinbefore
specified.
Of course, the condensation of alkylised diamido benzhydrols and the said
dinaphthylamine sulpho acids, the oxidation of the resulting leuco products, the
process of sulphonating the first obtained leuco compounds, and the conversion of
the so-formed sulphonated leuco products into dye stuffs by oxidation, can be
varied; for instance, the methods in general use for such purposes can also be
employed.
The modifications which follow from the last named Examples IV, V, and VI,
and likewise those which follow from the above Examples I, II, and III, do not
alter the nature of this invention, which in general relates to the production of
leuco compounds, sulphonated leuco products, and dye-stuffs from these leuco
compounds and sulphonated leuco products, by means of alkylised diamidobenz-
hydrols and naphthylamine sulpho acids, substituted naphthylamine sulpho acids
(containing the substituents in the naphthalene nucleus), monoalkylnaphthylamine
sulpho acids, dialkylnaphthylamine sulpho acids, or dinaphthylamine sulpho acids;
and to the manufacture of the last named dinaphthylamine sulpho acids, for the
hereinbefore defined, or other dye stuff combinations.
Of alkylised diamidobenzhydrols, all those known hitherto can be employed, for
instance, tetramethyldiamidobenzhydrol, tetraethyl diamidobenzhydrol, dimethyl-
diethyldiamido, benzhydrol, dimethyldibenzyldiamido benzhydrol, diethyldibenzyl
diamido benzhydrol, trimethylmonobenzyldiamido benzhydrol, triethylmonobenzyl-
diamido benzhydrol, dimethylethylbenzyldiamido benzhydrol, diethylmethyl benzyl-
diamido benzhydrol. In like manner, in the processes of producing leuco
products and dye stuffs described in this Specification, and in the Specifications of
my applications for Letters Patents No. 14728 and No. 19246 of 1882, before
mentioned, sulpho derivatives and other substitution products of alkylised diamido
benzhydrols, can also be employed, for instance, the tetramethyldiamido benz-
hydroldisulpho acid (described in the German Patent No. 65017) and analogues
thereof.
The process of producing leuco products, so-called sulphonated leuco products,
and dye stuffs, by means of the said sulpho derivatives, or other substitution
derivatives, of alkylised diamido benzhydrols, and the sulpho acids hereinbefore
specified (riz., naphthylamine sulpho acids, substituted naphthylamine sulpho acids,
containing the substituents in the naphthalene nucleus, mono alkyl- and dialkyl-
naphthylamine sulpho acids, and dinaphthylamine sulpho acids), is effected in the
same manner as described in the above Examples II, III, IV, V, and VI, and the
analogous leuco products, sulphonated leuco products, and dye stuffs, from the said
sulpho derivatives, or other substitution derivatives of alkylised diamido benz-
hydrols, and the sulpho acids mentioned in the Specifications of applications for
Letters Patent No. 14728 and No. 19246 of 1892; may also be produced by means
of the methods illustrated in the last named two Specifications.
Dated this 21st day of November 1892.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to the Manufacture and Production of
Diphenylnaphthylmethane Dyes.
I HENRY EDWARD NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, 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:-
My foreign correspondents have found, that leuco products and dye-stuffs of the

page_text: diphenylnaphthylmethane series can be produced by combining alkylised diamido
benzhydrols with certain alphanaphthylamine sulpho acids, and either directly
oxidising the leuco products thus formed, or previously sulphonating the resulting
leuco compounds, and subsequently oxidising the sulphonated leuco compounds
thus produced.
The researches of my foreign correspondents have shown that the alpha
naphthylamine sulpho acids which contain a sulpho group, and the amido group,.
relatively, in the ortho position, are of special value for this purpose. Such
alphanaphthylamine sulpho. acids, are, for example, alpha-naphthylamine-
ortho-monosulpho acid (NH₂SOH = 1:2), alphanaphthylamine disulpho acid
(NH,SO,H: SO,H=1:2:7), alphanaphthylaminetrisulpho acid (NH,SO,H:
SO,H: SO,H=1:2:4:7, the numeration of these alpha-naphthylamine sulpho
acids being based on the following scheme:
The process for obtaining these leuco products and dye-stuffs is, in general,
analogous to that which my foreign correspondents have described in the Specifi-
cation of my application for Letters Patent No. 14728, dated 15th August 1892.
The leuco derivatives produced from alkylised diamido benzhydrols, and the alpha-
naphthylamine sulpho acids hereinbefore specified, may, with advantage, be
previously subjected to treatment with sulphonating agents, and the sulphonated
leuco products thus obtained may then be oxidised.
The process for producing leuco compounds and dyestuffs from alkylised
diamidobenzhydrols, and the above named alphanaphthylaminesulpho acids, is
illustrated by the following example: The parts are by weight.
PRODUCTION OF A LEUCO PRODUCT AND DYE-STUFF
DIAMIDOBENZHYDROL
ACID.
AND
FROM TETRAMETHYL-
ALPHANAPHTHYLAMINEORTHOMONOSULPHO.
45 parts of alphanaphthylamineorthomonosulpho acid are mixed with 5-4 parts:
of tetramethyldiamido benzhydrol, and about 40 parts of water acidulated with.
5 parts of sulphuric acid (at 66 degrees Baumé). The resulting mixture is heated,.
during a short time, at from about 80 to 90 degrees centigrade, until tetramethyl-
diamido benzhydrol is no longer distinguishable. The mass is then poured into
about 20 parts of water, and a small excess of sodium carbonate, is added. The
sodium salt of the resulting leuco monosulpho product separates in white scales,
which dissolve with difficulty in cold water. It is more readily soluble in boiling
water, separating in crystals, on cooling the hot solution.
following formula :-
It possesses the

page_text: :
In order to oxidise this leuco product, 248 parts of the dry sodium salt are
dissolved in strong acetic acid, together with a small quantity of diluted muriatic
acid, and 4 parts of a paste containing 30 per cent. of pure lead dioxide are added
to the resulting solution.
The separated dyestuff is filtered off and redissolved in diluted sulphuric acid.
After filtering off the insoluble lead sulphate, the colouring-matter is salted out
from the solution by adding common salt to the filtrate. It produces blue shades
on wool in acid baths.
The composition of the dyestuff thus produced is represented by the following
formula :-
CH-N(CH),
OH.CC.H₁-N(CH,),
NH,
CH
SO,Na.
The process of converting the leuco monosulpho acid first produced, into the
leuco polysulpho acid, and the conversion of the latter into the corresponding
dye stuff by oxidation, is illustrated by the following example, the parts mentioned
hoing by weight
CONVERSION
OF THE LEUCO PRODUCT (OBTAINABLE AS DESCRIBED IN THE
FOREGOING FIRST EXAMPLE) INTO THE CORRESPONDING LEUCO POLY-
SULPHO ACID, AND OF THE LATTER INTO THE DYESTUFF BY OXIDATION.
4.75 parts of the sodium salt of the lecuo compound obtained as described in the
foregoing first example from tetramethyldiamidobenzhydrol and alphanaphthyl-
amine orthomonosulpho acid, are gradually stirred into 19 parts of fuming sulphuric
acid (containing 30 per cent. of sulphuric anhydride), and the resulting liquid
mixture is heated during about 36 hours, at 30 degrees centigrade. When
sulphonation is complete, the mixture is poured onto ice, and the sulphuric acid
contained in the resulting solution is neutralised with sodium carbonate. The
sodium salt of the new leuco disulpho acid separates, together with sodium sulphate,
in the form of a cystalline mass. This mass having been dissolved in hot water,
calcium carbonate or slaked lime is added to the solution, in order to get rid of the
sulphate. The solution containing the sodium salt of the leuco disulpho acid is
then filtered off from the precipitated calcium sulphate (gypsum). The sodium
salt of the leuco disulpho acid thus produced is represented by the following
formula :-

page_text: added to such a quantity of water, that the whole quantity of water employed is
50 parts. 25 parts of a wet paste containing 10 per cent. of pure lead dioxide mixed
with 15 parts of diluted acetic acid containing 50 per cent. of pure acetic acid, are
then gradually stirred into the solution.
•
The formation of the dyestuff is complete within a short time. After adding
5 parts of sodium sulphate, the resulting lead sulphate is filtered off'; the solution
of the dyestuff is evaporated to dryness, and the residue finely ground.
The colouring matter thus obtained is probably represented by the following
formula: --
CH-N(CH),
OH.C
-CH、 – N (CH¸),
NH,
CH. SO,Na
C₁H
SO,Na.
It yields clear blue shades which withstand the action of alkalies and acids.
Analogous colouring matters result if, in the above first example, either another
alkylised diamidobenzhydrol (such as tetrethyldiamidobenzhydrol be used, in
place of tetramethyldiamidobenzhydrol, or if the alpha-naphthylamine ortho mono-
sulpho acid be replaced by the corresponding quantities of other alphanaphthyl-
amine sulpho acids, containing a sulpho group and the amido group, relatively, in
ortho position.
If, for instance, tetrethyldiamidobenzhydrol is condensed with alphanaphthyl-
amine-ortho-mono sulpho acid (NH, : SO,H = 1 : 2) and the leuco sulpho product
thus obtained is oxidised, a dye stuff results which also produces pure blue shades
on wool in acid baths.
In cases in which it is desired to convert the leuco sulpho compounds first
produced into more highly sulphonated leuco products, and subsequently to oxidise
these, the processes of further sulphonation and oxidation can be effected in a
manner analogous to that described in the above second example.
The employment of naphthylamine polysulpho acids for the production of leuco
sulpho products and colouring matters therefrom, is illustrated by the following
example. The parts are by weight.
COLOURING MATTER FROM TETRAMETHYLDIAMIDOBENZHYDROL AND ALPHA-
NAPHTHYLAMINETRISULPHO ACID NH, SO,H: SO,H: SO,H = 1:2:4: 7.
:
4-4. parts of the calcium salt of the alphanaphthylaminetrisulpho acid
NH, SO,H: SO,H: SO,H=1:2:4:7, are mixed with 2:7 parts of tetra-
methyldiamidobenzhydrol, 6-4 parts of sulphuric acid (containing 10 per cent. of
pure sulphuric acid), and 8.8 parts of acetic acid (containing 50 per cent. of pure
acetic acid). The resulting mixture is heated for some hours by means of a water
bath (the mass being kept stirred), until tetramethyldiamidobenzhydrol is no
longer distinguishable. The hot liquid is then filtered. The leuco sulpho product
which separates as the filtrate cools, is filtered off, and 19 parts of the product are
dissolved in about 200 parts of water, and the necessary quantity of alkali. 28 parts
of a wet paste of lead dioxide containing 30 per cent. of the pure dioxide are stirred
in, and 25 parts of acetic acid containing 50 per cent. of pure acetic acid, are then
added, whilst the mixture is well agitated. The formation of the dye stuff at once
takes place. It can be isolated in the manner described in the above first
example.

page_text: The coloring matter thus obtained produces beautiful blue shades on wool, which
withstand the action of alkalies. It is also distinguished by its property of striking
slowly on the fibre, yielding, by reason thereof, very even shades.
My foreign correspondents have ascertained that the colouring matter produced
in the aforesaid manner is identical with the dye-stuff obtainable in an analogous
manner from tetramethyldiamidobenzhydrol and alpha naphthylaminedisulpho
acid (NH, SO,H SO,H=1:2:7).
Hence it follows, that on condensing tetramethyldiamidobenzhydrol with the
said naphthylaminetrisulpho acid, one of the sulpho groups is separated. In
order to ascertain whether the sulpho group in the position 2 or 4 in the alpha-
naphthylaminetrisulpho acid is separated, my foreign correspondents have prepared
the leuco sulpho product from tetramethyldiamidobenzhydrol, and the alpha-
naphthylaminedieulpho acid NH, SO,H: $0,H=1:47, and they have found
that, on a further oxidation, this leuco compound yields a colouring matter which
materially differs from the dyestuff obtained from tetramethyldiamidobenzhydrol,
aud either alphanaphthylaminetrisulpho acid (NH,: SO,H,SO,H,SO,H=1:2:4:7)
or alpha naphthylaminedisulpho acid (NH, SO,H SO H 1:27). It therefore
follows, that on acting with tetramethyldiamidobenzhydrol on the said alpha
naphthylaminetrisulpho acid, the sulpho group which is split off, is that which
occupies the position 4 in the latter acid, and that consequently the colouring
matters obtainable from alkylised diamidobenzhydrol, and either alphanaphthyl-
aminetrisulpho acid NH, SO,H: SO,H: SO,H=1:2:4:7, or alphanaphthyl-
aminedisulpho acid NH, SO,H SO,H=1:2:7, are identical.
:
=
My foreign correspondents have described in the above examples several methods
of producing the leuco sulpho compounds and coloring matters herein before defined,
but they do not limit themselves to the directions given therein, as the latter can be
varied. For instance, in the above first example, the alphanaphthylamine ortho-
monosulpho acid therein employed, can be replaced by the corresponding quantities
of alkaline salts thereof; the temperature may be raised or lowered within certain
limits; and correspondingly, the time requisite to effect the action can be shortened
or extended; and the isolation of the leuco product and dyestuff obtained as
described in the said example, can be effected by means of all the methods known
to chemists, and in use for such or similar purposes. The process described in the.
above second example, of further sulphonating the leuco sulpho products, can also
be effected by means of other sulphonating agents. The oxidation of the leuco
products can be carried out by means of other suitable oxidising agents.
Such or similar modifications do not alter the nature of this invention, as the
latter in general relates to the production of diphenylnaphthylmethane leuco-
products and colouring matters, by means of alkylised diamidobenzhydrols, and
such alphanapthylaminesulpho acids as contain a sulpho group and the amido group,
relatively, in the ortho position.
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 from
abroad), I declare that what I claim is :
1. The production of leuco compounds and dye-stuffs of the diphenylnaphthyl-
methane series from alkylised diamidobenzhydrols, and such alphanaphthylamine
sulpho acids as contain a sulpho group, and the amido group, relatively, in the ortho
position.
2. The process of obtaining leuco compounds of the diphenylnaphthylmethane
series, by acting with alphanaphthylamine ortho mono sulpho acid (NH,SO,H=1:2),
alpha naphthylaminedisulpho acid (NH, SO,H.SO,H =1: 2: 7), or alphanaphthyl-
aminetrisulpho acid (NH,: SO,H: SO,H: SO,H=1:2:4:7), or alkaline salts
thereof, on the following alkylised diamidobeuzhydrols or salts thereof :-tetra-
methyldiamidobenzhydrol, or tetrethyldiamidobenzhydrol.
3. The conversion of the leuco compounds produced as described in the foregoing
second claim, or by any other way, into more highly sulphonated products, by

page_text: heating them with fuming sulphuric acid, or other agents producing the same or a
similar result.
4. The process of transforming the leuco compounds of the diphenylnaphthyl-
methane series, produced as described in the preceding second and third claim, or
by any other way, into the corresponding diphenylnaphthylmethane dyestuffs by
oxidation.
5. As new products of manufacture, the new leuco sulpho compounds and coloring
matters of the diphenylnaphthylmethane series, produced by means of the processes
hereinbefore defined, or by any other process affording the same result.
Dated this 21st day of August 1893.
NEWTON & SON,
Agents for the Applicant.