The Manufacture and Production of New Basic Dyes, and of New Materials for use in their Preparation.
Year: 1892

page_text: Date of Application, 19th Dec., 1892
Complete Specification Left, 5th Sept., 1893-Accepted, 21st Oct., 1893
PROVISIONAL SPECIFICATION.
The Manufacture and Production of New Basic Dyes, and of New
Materials for use in their Preparation.
I JAMES. YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this invention which has been com-
municated to me from abroad by The Badische Anilin and Soda Fabrik of
Ludwigshafen on Rhine in the Empire of Germany to be as follows:-
This invention relates to the manufacture of new mono alkylated amido-cresols
and to their conversion into dialkylated rhodamines and finally to the conversion of
these dialkylated rhodamines into other new red basic dyes.
The said new mono alkylated amido cresols are obtained from mono alkylated
ortho-toluidines which are first converted into sulpho acids by treatment with
fuming sulphuric acid whereby mono-alkyl-ortho-toluidine-para-sulpho-acids
are obtained. The next step consists in melting these sulpho acids or rather their
alkaline salts with a caustic alkali so as to convert them into the corresponding
mono-alkyl-ortho-amido-para-cresols
In these compounds the amido and hydroxy groups are in the meta-position to
one another and the bodies can be used in the preparation of new rhodamine dyes
the conversion into these dyes (which are symmetrical dialkylated rhodamines)
being effected by condensation with phthalic anhydride in a manner analogous to
that described in the Specification of Letters Patent No. 15374 of 1887 granted to
me. The new rhodamines so obtained are higher homologues of those described in
the Specification of the German Patent 48731 and may therefore be called
homo-rhodamines. Finally by treating the new symmetrical di-alkylated rhod-
amines of the phthalic series in such a manner as to cause them to combine with a
further proportion of alkyl, other new basic rhodamine dyes are obtained. A
similar proceeding to this latter but as applied to other dialkylated rhodamines is
described in the application for Patent No. 9633 of 1892.
The following examples are intended to further illustrate the nature of the
invention but they are capable of variation in many respects and I therefore do not
limit myself to the precise details.
PRODUCTION OF A NEW
MONO-ALKYL-ORTHO-TOLUIDINE PARA-SULPHO-
ACID.
Mix about ten parts of mono-ethyl-ortho-toluidine with about twenty parts of
fuming sulphuric acid containing about twenty three per cent. free anhydride taking
care that the temperature at no time exceeds about sixty degrees centigrade.
Next (while still carefully cooling) add about thirty parts of fuming sulphuric
acid containing about seventy per cent. free anhydride. Allow the mixture to stand
at a temperature of from forty to seventy degrees centigrade till a test portion is
The greater
completely soluble in alkaline water, then pour the whole onto ice.
part of the new sulpho acid usually separates out directly in the crystalline form.
Convert into the sodium salt in the usual way.

page_text: Mix together about ten parts of mono-ethyl-ortho-amido-para-cresol ten
parts of phthalic anhydride and about five parts of zinc chloride and melt the
mixture in an enamelled pot excluding air as far as practicable. Maintain the
temperature at about one hundred and seventy to two hundred degrees centigrade
for about an hour or until the melt shows a tendency to solidify. When cold reduce
to powder wash well with water to extract zinc chloride then mix the residue well
with an excess of dilute caustic soda solution and digest for twenty four hours.
Collect the homorhodamine base thus obtained on the filter wash and dry. The
base can be converted into its hydrochlorate by dissolving in concentrated
hydrochloric acid and pouring out into a limited quantity of water. Other dialkyl-
homo rhodamines and in particular the dimethyl-compound, can be obtained in the
same way from the corresponding mono alkyl-amido cresol.
EXAMPLE 4.
PRODUCTION OF THE NEW BASIC DYES BY FURTHER ALKYLATING THE NEW
DIALKYL HOMORHODAMINES.
The procedure for obtaining these new dyes is the same as that described in the
Specification of the aforesaid application for Patent No. 9633 of 1892 as applied
to other dialkylated rhodamines. The said new dyes may be obtained by dissolving
the homo-rhodamine in alcohol and treating with hydrochloric acid or by heating
a salt of a homorhodamine (under pressure if necessary) with alcohol or by
treating a homo-rhodamine base with an alkyl chloride or other halogen compound
of alkyl.
Dated this 19th day of December 1892.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London.

page_text: COMPLETE SPECIFICATION.
The Manufacture and Production of New Basic Dyes, and of New
Materials for use in their Preparation.
I, JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of
Middlesex Gentleman do hereby declare the nature of this invention (which has
been communicated to me from abroad by The Badische Anilin and Soda Fabrik
of Ludwigshafen on Rhine in the Empire of Germany) and in what manner the.
sane is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention relates to the manufacture of new mono-alkylated amido-cresols
and to their conversion into dialkylated rhodamines and finally the conversion of
these dialkylated rhodamines into other new red basic dyes.
The said new mono-alkylated amido-cresols are obtained from mono-alkylated
ortho-toluidines, which are first converted into sulpho-acids by treatment with
fuming sulphuric acid, whereby mono-alkyl-ortho-toluidine-para-sulpho-acids are
obtained. The next step consists in melting these sulpho acids or rather their
alkaline salts with a caustic alkali, so as to convert them into the corresponding
mono-alkyl-ortho-amido-para-cresols.
PRODUCTION OF A NEW
MONO-ALKYL-ORTHO-TOLUIDINE-PARA-SULPHO-
ACID.
Mix about ten parts of mono-ethyl-ortho-toluidine with about twenty parts of
fuming sulphuric acid containing about twenty three per cent. free anhydride, taking
care that the temperature at no time exceeds about sixty degrees centigrade.
Next (while still carefully cooling) add about thirty parts of fuming sulphuric
acid, containing about seventy per cent. free anhydride. Allow the mixture to stand
at a temperature of from forty to seventy degrees centigrade till a test portion is
The greater
completely soluble in alkaline water; then pour the whole onto ice.
part of the new sulpho-acid usually separates out directly in the crystalline form.
Convert into the sodium salt in the usual way.

page_text: PRODUCTION OF THE NEW BASIC DYES BY FURTHER ALKYLATING THE NEW
DIALKYL-HOMO-RHODAMINES.
The procedure for obtaining these new dyes (which are chemically dialkyl-homo-
rhodamine-alkyl-esters) is the same as that described in the Specification of the
aforesaid Letters Patent No. 9633 of 1892 granted to me. They may be obtained
by dissolving the homo-rhodamine in an alcohol (such as methyl, ethyl and amyl,
alcohol, glycerol, and the like) and treating with hydrochloric acid; or by heating
a salt of a homo-rhodamine (under pressure if necessary) with an alcohol; or by
treating a homo-rhodamine base with an alkyl-chloride or other halogen compound
of alkyl and the like (such for instance as the halogen derivatives of methyl,
ethyl, amyl, benzyl, methylene, and ethylene).

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The manufacture of new basic dyes by first converting a mono-alkylated-
ortho-toluidine into its para-sulpho acid by sulphonation then converting this into
the corresponding hydroxy-compound by means of caustic alkali and finally
converting the mono-alkylated ortho-amido-para-cresol so obtained into a rhodamine
dye all substantially as herein before described.
2. The manufacture of new basic dyes by first preparing a rhodamine dye of the
phthalic acid series by the series of operations set forth and claimed in the foregoing
claiming clause and then combining it with a further proportion of alkyl all
substantially as hereinbefore described.
3. The manufacture of mono-alkyl-ortho-toluidine-para-sulpho-acid substantially
in the manner hereinbefore described under Example 1.
4. The manufacture of mono-alkylated-amido-cresols substantially in the manner
hereinbefore described under Example 2.
5. The manufacture of dialkylated homo-rhodamine substantially in the manner
herein before described under Example 3.
6. The application of the processes described in the Specification of Letters
Patent No. 9633 of 1892 to dialkylated homo-rhodamines in the manner herein
before described under Example 4.
7. As new articles of manufacture, mono-alkyl-ortho-toluidine-para-sulpho-acid;
mono-alkylated-amido-cresols; dialkyl-homorhodamine; and dialkyl-homo-rhod-
amine-alkyl-esters all substantially such as can be obtained as hereinbefore
described.
D
1