Production of Dehydrothioaniline Sulphonic Acid and of Coloring Matters therefrom.
Year: 1894

page_text: Date of Application, 12th Nov., 1894
Complete Specification Left, 12th Aug. 1895-Accepted, 14th Sept., 1895
Production of Dehydrothioaniline Sulphonic Acid and of Coloring
Matters therefrom.
We, ARTHUR GEORGE GREEN F.I.C., F.C.S., of 13 Kings Drive, Heaton
Moor, Stockport, and ROBERT JANSEN Ph. D., of 16 The Grove, Victoria Park,
Manchester, Chemists to The Clayton Aniline Co. Ld., Aniline Dye Manufacturers
of Clayton, in the County of Lancaster, do hereby declare the nature of our invention
to be as follows:-
In French Patent 216086 of 1891 the Société Anonyme des matières colorantes
de St. Denis describe the preparation of the lower homologue of dehydrothio-
toluidine by heating a mixture of paratoluidine and aniline with sulphur. This
base which may be termed provisionally "dehydrothioaniline" does not appear to
have yet obtained practical employment in the preparation of dyestuffs. We have
now found that by treatment with fuming sulphuric acid or other suitable
sulphonating agents this base is converted into a sulphonic acid which by com-
bination with the usual dyestuff components yields valuable coloring matters.
dehydrothioaniline sulphonic acid which probably has the constitution
The
is a nearly white precipitate sparingly soluble in water with a blue fluorescence and
forming easily soluble colorless salts with the alkali metals. The ammonium salt
in contradistinction to the sparingly soluble ammonium salt of dehydrothiotoluidine-
sulphonic acid dissolves readily in water and crystallizes in small colourless
needles. The copper salt is reddish brown. The diazo compound is a sulphur-yellow
precipitate.
The dehydrothioaniline sulphonic acid may be converted into colouring matters
by one of the following two methods :-
(a) By combination with certain diazo compounds.
(b) By diazotisation and combination of the diazo derivative with such amines,
phenols, amidophenols, amidophenol-ethers, or their respective sulphonic or
carboxylic acids, as have hitherto been employed as dyestuff components in
combination with diazo compounds. As illustrating the general method of carrying
out this invention the following examples may be given.
PREPARATION OF DEHYDROTHIOANILINE.
A mixture of 107 lbs. of paratoluidine and 140 lbs. of aniline are heated with
128 lbs. of sulphur for 24 hours, until the loss of hydric sulphide amounts to about
103 lbs., and the temperature has risen to 240° C. For the preparation of the pure
base the melt is distilled and the distillate is treed from aniline and crystallized
from amyl alcohol. It forms small yellowish prismatic crystals which melt constantly
at 151° C.

page_text: PREPARATION OF DEHYDROTHIOANILINE SULPHONIC ACID.
100 lbs. of the above base are dissolved in 400 lbs. of ordinary sulphuric acid
(95%) and 400 lbs. of fuming sulphuric acid (70% free SO,) are slowly added, the
temperature being kept below 50° C. When the sulphonation is complete (i.e. when
a test sample dissolves clear in soda) the product is poured into a large bulk
of water and the precipitated sulphonic acid is filtered off, washed free from
sulphuric acid, and converted into the sodium salt by neutralisation with soda.
PREPARATION OF A DIAZOAMIDE COLOUR.
13 lbs. of paranitraniline are diazotised in the usual manner with 7 lbs. of
sodium nitrite. The p-nitrodiazobenzene is then run into a cold solution of 32 lbs.
of sodium dehydrothioaniline-sulphonate kept alkaline by addition of sodium
carbonate.
After standing for several hours the mixture is warmed up to about
70° C. and the colouring-matter precipitated by salt. It dyes unmordanted cotton
a greenish yellow from an alkaline bath. In place of paranitraniline other amines
may be used such as nitro-o-toludine (1:2:5), nitrobenzidine, dehydrothiotoluidine
sulphonic acid, dehydrothioxylidine sulphonic acid, benzidine sulphonic acids, etc.
PREPARATION OF AN AZO COLOUR.
32 lbs. of sodium dehydrothioaniline sulphonate are dissolved in 100 gallons of
water, 7 lbs. of sodium nitrite are added, and the mixture is acidified with
2 gallons of hydrochloric acid (30%). The diazo compound is then added to a
solution of 14 lbs. of ẞ-naphtol, 4 lbs. of caustic soda, and 10 lbs. of conc.
ammonia, in 50 gallons of water. The colouring matter is filtered off and dried.
It dyes wool red from an acid bath. In place of B-naphtol in the above example
there may be employed any of the usual dyestuff-components, such as a-naphtol,
the mono-, di-, or trisulphonic acids of a- and ẞ-naphtol, that are capable of
combining with diazo compounds, a- and ẞ-naphtylamine and their sulphonic acids,
the various amidonaphtols and their sulphonic acids, dioxy- and diamido-naphtalenes
and their sulphonic acids, alkyloxy-naphtol sulphonic acids, alkyloxy-naphtylamine
sulphonic acids, oxynaphthoic acids, phenol, cresols, salicylic acid, cresotinic acid,
m-phenylene diamine, toluylene diamine (1:2:4), m-phenylene-diamine-disulphonic
acid, m-amidophenol, resorcin, chrysoidine, Bismarck brown, etc.
Moreover the diazotised dehydrothioaniline sulphonic acid may be used as one
component of a bisazo, trisazo, or tetrakisazo compound of which the other
components consist of known compounds.
Dated this 10th day of November 1894.
A. G. GREEN.
ROBERT JANSEN.
Production of Dehydrothioaniline Sulphonic Acid and of Coloring
Matters therefrom.
We ARTHUR GEORGE GREEN, and ROBERT JANSEN, both of Clayton
Manchester, Chemists, 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 :-
In the Specification of the French Patent 216086 of 1891 the Société Anonyine
des matières colorantes de St. Denis describe the preparation of the lower
homologue of dehydrothiotoluidine by heating a mixture of paratoluidine and aniline

page_text: with sulphur. This base (which may be termed dehydrothioaniline) does not
appear to have yet been practically employed in the preparation of dye stuffs.
We have now found that by treating this base with fuming sulphuric acid, or other
suitable sulphonating agents, it is converted into a sulphonic acid which, by
5 combination with the usual dye-stuff components, yields valuable colouring matters.
The dehydrothioaniline sulphonic acid, which probably has the constitution

page_text: water, 7 lbs. of sodium nitrite are added, and the mixture is acidified with
24 gallons of hydrochloric acid (30 per cent.). The diazo compound is then added
to a solution of 14 lbs. of beta-naphthol, 4 lbs. of caustic soda, and 10 lbs. of
strong ammonia, in 50 gallons of water.
The colouring matter is filtered off and dried. It dyes wool, red from an acid
bath. In place of beta-naphthol in the above example, there may be employed
any of the usual dyestuff components such as alpha naphthol, the mono- or di-
sulphonic acids of alpha- and beta-naphthol, alpha and beta-naphthylamine and
their sulphonic acids, the various amidonaphthols and their sulphonic acids, dioxy
and diamido-naphthalenes, and their sulphonic acids, àlkyl-oxy-naphthol sulphonic
acids, alkyl-oxy-naphthylamine sulphonic acids, oxy-naphthoic acids, phenol,
cresols, salicylic acid, cresotinic acid, meta-phenylene-diamine, toluylene-diamine
(123), meta-phenylene diamine disulphonic acid, meta amido phenol, resorcin,
chrysoidine Bismarck brown, and the like. Moreover the diazotised dehydro-
thioaniline sulphonic acid may be used as one component of a bisazo or trisazo
compound of which the other components consist of known dye-stuff components.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is: :-
1. The manufacture of the sulphonic acid (and its salts) of the thio base, herein-
before termed dehydrothioaniline, by treating the said base with fuming sulphuric
acid, or other suitable sulphonating agents.
2. The manufacture of colouring matters by the combination of the sulphonic
acid of dehydrothioaniline (or its salts) with the diazocompounds of paranitraniline
or of other amines, as herein before stated.
3. The manufacture of colouring matters by diazotising the sulphonic acid of
dehydrothioaniline and combining the diazo compound with amines, phenols,
amido-phenols, amido-phenol ethers, or their respective sulphonic, or carboxylic acids,
or other usual dye stuff components as hereinbefore stated.
4. The manufacture of dehydrothioaniline sulphonic acid as hereinbefore described
under the Example I.
5. The manufacture of diazoamido colouring matters as hereinbefore described
under the Example II.
6. The manufacture of azo colouring matters as hereinbefore described under the
Example III.
7. As new articles of manufacture the sulphonic acid of dehydrothioaniline and
its salts hereinbefore described, whether produced by the process hereinbefore
given, or by any other process affording the same result.
8. As new articles of manufacture the colouring matters such as can be produced
according to the preceding second, third, fifth, and sixth, claiming clauses,
whether produced by the process hereinbefore given, or by any other process
affording the same result.
Dated this 12th day of August 1895.
JOHNSONS & WILLCOX,
Agents.