The Manufacture or Production of Naphthafluoresceine.
Year: 1895

page_text: Date of Application, 18th Feb., 1895
Complete Specification Left, 18th Nov., 1895-Accepted, 21st Dec., 1895
[Communicated from abroad by THE FARBENFABRIKEN, vormals FRIEDRICH
BAYER & Co., of Elberfeld, Germany.]
The Manufacture or Production of Naphthafluoresceine.
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:-
The object of this invention is to produce fluoresceine of the naphthalene
serics.
My foreign correspondents have found that the naphthafluoresceine can be easily
obtained from naphtharesorcinol (meta dihydroxynaphthalene) which is produced,
for instance, by heating with water or dilute acids, at elevated temperatures, beta-
amido-alpha-naphthol-alpha, sulphonic acid, or beta, alpha-dihydroxynaphthalene-
alpha, sulphonic acid (alpha, beta, dihydroxynaphthalene-alpha, sulphonic acid), or
salts thereof. According to the researches of my foreign correspondents, the
naphtharesorcinol, when condensed with phthalic acid, phthalic acid anhydride, or
the like, in the presence of condensing agents (such as concentrated sulphuric acid,
zine chloride, oxalic acid, or the like), is converted into naphthafluoresceine, in the
same manner as the typical fluoresceine results from resorcinol.
My foreign correspondents briefly term the fluoresceine of the naphthalene
series, "naphthafluoresceine."
The processes for producing naplithafluorescüine are analogous to those known
and in use for producing the fluorescüine from resorcinol. One of the methods for
preparing this naphthafluoresceine is illustrated by the following example, the parts
being by weight.
EXAMPLE.
45 parts of naphtharesorcinol are mixed with 25 parts of phthalic anhydride and
20 parts of zine chloride. The resulting mixture is heated during about 10 hours,
at, 200 degrees Centigrade. It becomes stiff, and assumes a reddish-brown colour
and metallic lustre. After cooling, the brittle mass is pulverized, and treated, with
boiling water containing muriatic acid. The residue is dissolved in dilute soda lye.
This alkaline solution, when cold,. is acidulated with sulphuric acid, and the
precipitate thus formed is filtered off and pressed. The moist press-cake is treated
with ether, which dissolves out. a black resin, the naphthafluoresceine remaining in
little brown crystals. The naphthafluoresceine thus formed is then purified by
crystallization from alcohol.
It forms little brown needles, mostly shewing a green metallic lustre, owing to
the adherent mother-liquor. It does not melt, and is insoluble in benzene, but is
soluble with difficulty in ether, and soluble with ease in alcohol. It is precipitated
in the form of brown flakes, on adding water to its alcoholic solution.
Lis solutions possess a yellowish-red colour and an intense green. fluorescence,
which appears with special distinctness on adding a small quantity of any acid to
its alcoholic solution. It dissolves in alkalies, affording mageuta-red coloured
solutions which exhibit a yellow fluorescence.

page_text: The naphthafluoresceine hereinbefore defined, yields, on silk, rose-like shades,
with a yellow fluorescence.
According to the researches of my foreign correspondents, the naphthafluoresceine
can be used for producing other dye-stuffs.
Dated: 10 31
NEWTON & SON,
Agents for the Applicant..
The Manufacture or Production of Naphthafluorescëine.
I HENRY EDWARD NEWTOx 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 :-
The object of this invention is to produce the fluorescüine of the naphthalene
series.
My foreign correspondents have found that naphthafluoresceine can be easily
obtained from naphtharesorcinol (metadihydroxynaphthalene), which is produced,
for instance, by heating with diluted mineral acids, at elevated temperatures, beta,
amido alpha, naphthol alpha, sulphonic acid, or beta, alpha, dihydroxynaphthalene
alpha, sulphonic acid (alpha, beta, dihydroxynaphthalene alpha, sulphonic acid),
or salts thereof. When this naphtharesorcinol is acted on by phthalic acid,
phthalic acid anhydride, or the like, in the presence of condensing agents (such as
concentrated sulphuric acid, zine chloride, phosphoric anhydride, oxalic acid, or
the like), it is converted into naphthafluoresceine in the same way resorcinol is
acted on, and converted into the typical fluoresceine.
:
My foreign correspondents briefly term the fluoresceine of the naphthalene
series, "naphtha fluoresceine."
The process for producing naphthafluoresceine are analogous to those used in
producing fluoresceine from resorcinol. One of the methods is illustrated by the
following example, the parts being by weight.
EXAMPLE.
45 parts of naphtharesorcinol are mixed with 25 parts of phthalic anhydride and
20 parts of zinc chloride, and the mixture is heated during about 10 hours at
200 degrees Centigrade. It then becomes stiff, and assumes a reddish-brown
olor and metallic lustre. When cold, the brittle mass is pulverised, and after
extracting it with boiling water containing muriatic acid, the reddish-brown
residue is dissolved in dilute soda-lye. When cold, the alkaline solution thus
btained is acidulated with sulphuric acid, and the precipitate is filtered off and
ressed. The moist press' cake is digested with ether, which dissolves out a black
sin, leaving naphthafluoresceine in small brown crystals. The naphthafluoresceine
hus obtained is then purified by recrystallisation from alcohol.
It forms small red needles, which, as a rule, exhibit a green metallic lustre. It
does not melt. It is insoluble in benzene, and dissolves with difficulty in ether,
but with ease in alcohol. It is precipitated in the form of brown flocculi, on adding
water to its alcoholic solution.
Its solutions possess a yellowish red color, and an intense green fluorescence,
which appears with special distinctness on adding a small quantity of any acid to
is alcoholic solution. It dissolves in alkalies, affording magenta-red colored
solutions, which exhibit a yellow fluorescence.
.

page_text: The naphthafluoresceine hereinbefore defined yields, on silk, rose-like shades
exhibiting a yellow fluorescence.
According to the researches of my foreign correspondents, naphthafluoresceine
can be used for producing other dye-stuffs.
In producing naphthafluoresceine, my foreign correspondents do not limit
themselves to the directions given in the above example, as these can be varied.
The proportions used therein and the temperature can vary within certain limits,.
and other suitable condensing agents may be used in place of zinc chloride. Thus,
for instance, the naphthafluoresceine herein before defined can also be obtained on
heating for 10 hours, at about 130 degrees Centigrade, a mixture containing
45 parts of naphtharesorcinol, 25 parts of phthalic anhydride, and 40 parts of
phosphoric anhydride (P,O), the said parts being by weight. Such or the like
modifications do not alter the nature of the present invention, which, speaking
generally, relates to the production of naphthafluoresceine from naphtharesorcinol.
Having now particularly described and ascertained the nature of the said inven-
tion 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 naphthafluorescüine from naphtharesorcinol (metadihy-
droxynaphthalene).
2. The process for producing naphthafluoresceine, which process consists in
allowing phthalic anhydride to act on naphtharesorcinol, or metadihydroxy-
naphthalene, at elevated temperatures, in the presence of condensing agents.
3. As a new product of manufacture, naphthafluoresceine produced by the
process hereinbefore defined, or in any other manner affording the same result.
Dated this 12th day of November 1895.
NEWTON & SON,
Agents for the Applicant.