Manufacture of New Leuco-bases of the Triphenylmethane Series and of Colouring Matters therefrom.
Year: 1899

page_text: Date of Application, 27th July, 1899
Complete Specification Left, 14th Apr., 1900-Accepted, 26th May,
1900
PROVISIONAL SPECIFICATION.
Manufacture of New Leuco-bases of the Triphenylmethane Series
and of Colouring Matters therefrom.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Build-
ings, 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:-
It is known that ortho-toluidine and its alkyl derivatives when condensed
with hydrols in the presence of strong sulphuric acid yield condensation products
which are quite different from those which are formed when the condensation is
effected in the presence of dilute acid.
My foreign correspondents have now found that instead of ortho-toluiding
and its alkyl-derivatives, other amido-products of the benzene series may be used
in which the ortho-position to the amido-group is occupied by chlorine, bromine,
the nitro-group or the ethoxyl or methoxyl-group.
The following example may serve to illustrate this invention.
135 kilos. of tetramethyldiamidobenzhydrol are dissolved in 135 kilos. of
sulphuric acid monohyurate; into this solution, which is previously cooled to
about 0° C., 9 kilos. of ortho-anisidine sulphate are introduced. The mass is
stirred until the condensation is completed and then it is thrown on ice and
neutralised with sodium carbonate. The leuco-base, precipitated in this way,
may be purified by recrystallisation from ether; it forms needles, melting at
130° C. and yields by treatment with oxidising agents a green-blue dyestuff.
For the ortho-anisidine may be substituted, with a similar result, ortho-phene-
tidine, ortho-chloraniline, ortho-bromaniline, ortho-nitraniline or the correspond-
ing ortho-substitution products of alkyl-anilines.
This 27th day of July 1899
ABEL & IMRAY,
Agents for the Applicant.
Manufacture of New Leuco-bases of the Triphenylmethane Series
and of Colouring Matters therefrom.
I, CHARLES DENTON ABEL, of Birkbeck Bank Chambers, Southampton Build-
ings, 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

page_text: 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:
It is known that ortho-toluidine and its alkyl derivatives when condensed
with hydrols in the presence of strong sulphuric acid yield condensation products
which are quite different from those which are formed when the condensation is
effected in the presence of dilute acid.
My foreign correspondents have now found that instead of ortho-toluidine
and its alkyl-derivatives, other amido-products of the benzene series may be used
in which the ortho-position to the amido-group is occupied by chlorine, bromine,
the nitro-group or the ethoxyl or methoxyl-group.
The following examples illustrate this invention.
A. 13.5 kilos. of tetramethyldiamidobenzhydrol are dissolved in 135 kilos. of
sulphuric acid monohydrate; into this solution, which is previously cooled to
about 0° C., 9 kilos. of ortho-anisidine sulphate are introduced. The mass is
stirred until the condensation is completed and then it is thrown on ice and
neutralised with sodium carbonate. The leuco-base, precipitated in this way,
may be purified by recrystallisation from ether; it forms needles, melting at
130° C. For the ortho-anisidine may be substituted with a similar result, ortho-
phenetidine, ortho-chloraniline, ortho-bromaniline, ortho-nitraniline or the
corresponding ortho-substitution products of alkyl-anilines.
B. 19 kilos. of the leuco-base obtained in the way described in A from
tetramethyldiamidobenzhydrol and chloro-aniline are dissolved in 200 litres of
water and 105 kilos. of concentrated sulphuric acid. After refrigeration by
addition of ice 50 kilos. of peroxide of lead (containing 24 per cent.) are added
thereto at 5 to 10° C. The lead-sulphate is filtered off, and the dyestuff is
precipitated from the green solution obtained by means of common salt and
zinc-chloride. It dyes tannin-mordanted cotton green shades.
Instead of peroxide of lead other oxidising agents may be employed.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:―
1. The herein described manufacture of new leuco-bases of the triphenylme-
thane series by condensing with tetra alkyl-diamidobenzhydrols in the presence
of strong sulphuric acid, such amido-compounds of the benzene series as are
substituted in the ortho position to the amido-group by chlorine, bromine, the
nitro-group or the ethoxyl or methoxyl-group, or the corresponding ortho-sub-
stitution products of alkyl-anilines.
2. The leuco-bases manufactured as above set forth.
3. The herein described manufacture of colouring matters from the leuco-
bases referred to in Claim 1, by treating the said leuco-bases with oxidising
agents.
4. The colouring matters manufactured as above set forth.
Dated this 14th day of Anril 1900