Manufacture of Rhodamine Dialkyl-amides.
Year: 1897

page_text: Date of Application, 20th Jan., 1897
Complete Specification Left, 20th Oct., 1897-Accepted, 20th Nov.,
1897
PROVISIONAL SPECIFICATION.
Manufacture of Rhodamine Dialkyl-amides.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by The Farbwerke vormals: Meister
Lucius and Brüning of Hoechst a/ Main in the Empire of Germany, Chemical
Manufacturers,) to be as follows:-
--
My correspondents have discovered that dialkyl-amides, which may be obtained by
the successive reaction of rhodamines with oxychloride of phosphorus and dialkyl-
amines, are valuable dyestuffs.
The process may be applied to tetra- as well as to tri- anddi- alkyl rhodamines, and
as dialkyl-amines are, for instance, employed: diethyl-amine and diamyl-amine.
The process is as follows:-
1). 1 part by weight of diethyl rhodamine hydrochloride is mixed with 3 parts by
weight of oxychloride of phosphorus; the reaction thus produced is finished by heating
to 80° C.
The cooled brown-red mass is then treated with benzene to remove the excess of
oxychloride; an insoluble brownish-red oil remains behind, which is mixed with about
ten times the quantity of chloroform and diethylamine.
The mixture is heated for some time at about 50° C; the chloroform and excess of the
base is then distilled off, the residue is extracted with hot water, and from the
filtered solution the new dyestuff is precipitated as double salt of chloride of zine;
it is soluble in water with a yellowish-red colour and fluoresence; alkali carbonates
dissolve it unchanged, free alkalies decompose it easily.
2). 1 part by weight of tetraethylrhodamine hydrochloride is heated for about
2 hours with oxychloride of phosphorus in a refrigerator, whereupon the product of the
reaction is washed with benzene or heated in vacuo to remove the excess of oxy-
chloride. The residue is dissolved in chloroform, three times the quantity of
diamylamine is then added and cooled simultaneously.
After several hours heating on the water-bath, the chloroform and excess of diamyl-
amine are distilled off and the residue dissolved in diluted hydrochloric acid.
Chloride of zinc precipitates the new dyestuff from the filtered solution in the form
of a crystalline double salt, soluble in hot water with a bluish-red colour and yellow
fluorescence. The dyestuff behaves relatively to soda and free alkali like the analogous
diethylamide.
DALL
1000

page_text: Manufacture of Rhodamine Dialkyl-amides.
I, OLIVER IMRAY, formerly of No. 28 Southampton Buildings, but now of Birkbeck
Bank Chambers, Southampton Buildings, Chancery Lane, in the County of London,
Chartered Patent Agent, do hereby declare the nature of this invention (as com-
municated to me from abroad by the Farbwerke vormals: Meister Lucius and
Brüning of Hoechst a/ Main 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 :—
My correspondents have discovered that dialkyl-amides, which may be obtained by
the successive reaction of rhodamines with oxychloride of phosphorus and dialkyl-
amines, are valuable dyestuffs.
The process may be applied to tetra- as well as to tri-anddi-alkyl rhodamines, and
as dialkyl-amines are, for instance, employed diethyl-amine and diamyl-amines.
The process is as follows:-.
1.) 1 part by weight of diethylrhodamine hydrochloride is mixed with 3 parts by
weight of oxychloride of phosphorus; the reaction thus produced is finished by heating
to 80° C.
The cooled brown-red mass is then treated with benzene to remove the excess of
oxychloride; an insoluble brownish-red oil remains behind, which is mixed with
about ten times the quantity of chloroform and diethylamine.
The mixture is heated for some time at about 50° C; the chloroform and excess
of the base is distilled off, the residue is extracted with hot water, and from the
filtered solution the new dyestuff is precipitated as double salt of chloride of zinc; it
is soluble in water with a yellowish-red colour and fluorescence; alkali carbonates
dissolve it unchanged, free alkalies decompose it easily.
2). 1 part by weight of tetraethylrhod-amine hydrochloride is heated for about
2 hours with oxychloride of phosphorus in a refrigerator, whereupon the product of
the reaction is washed with benzene or heated in vacuo to remove the excess of oxy-
chloride. The residue is dissolved in chloroform, three times the quantity of
diamylamine is then added and cooled simultaneously.
After several hours heating on the water-bath, the chloroform and excess of
diamylamine are distilled off and the residue dissolved in diluted hydrochloric acid.
Chloride of zinc precipitates the new dyestuff from the filtered solution in the form
of a crystalline double salt, soluble in hot water with a bluish-red colour and yellow
fluorescence. The dyestuff behaves relatively to soda and free alkali like the analogous
diethylamide.
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 process for manufacture of dialkyl-amides of rhodamines by treating
rhodamines with oxychloride of phosphorus and then with aliphatic secondary amines,
substantially as described.
2. The dyestuffs manufactured as above set forth.
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