The Manufacture and Production of Mono and Di-phenetidin-citric Acids.
Year: 1895

page_text: Date of Application, 18th Jan., 1895-Accepted, 23rd Feb., 1895
COMPLETE SPECIFICATION.
The Manufacture and Production of Mono and Di-phenetidin-citric
Acids.
I, JAMES YATE JOHNSON of 47 Lincoln's Inn Fields, in the County of
London, Gentleman, do hereby declare the nature of this invention (which has
been communicated to me from abroad by Dr. F. Von Heyden-Nachfolger of
Radebeul, near Dresden, in the Empire of Germany) and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention relates to the manufacture and production of mono- and
di-phenetidin citric acids, compounds hitherto unknown in commerce. They are
formed by heating para-amido-phenetol with citric acid, and separating the water,
in accordance with either of the following equations, giving the reaction which
takes place in each case.
(COOL)
C,H,O (COOH), +NH,C,H, OC,H = H,O + C,H,O.CO.NHC,H,OCH.
C₂H, O (COOH), + NH,CH ОCH, = H₂O + C,H,O. CO.NHC,H,OCH,
42 parts by weight of citric acid are heated with 275 parts by weight
of para-amido-phenetol for a number of hours so as to attain a temperature of
from 100 to 200° Centigrade. The mass or mixture of these reagents is then
dissolved in a solution of soda. By adding hydrochloric acid to the filtered
solution, mono-phenetidin-citric acid is obtained as a precipitate and may be
obtained in the pure condition by being crystallized out from either chloroform or
water.
By increasing the quantity of para-amido-phenetol from 27.5 to 55 parts by
weight, i.e. doubling its quantity, the product which will result from the reaction
will be di-phenetidin-citric acid. The product of the reaction is then treated
with dilute soda lye, with the result that a sodium salt forms, which is soluble,
but with great difficulty, in the excess of soda lye.
This is filtered off and decomposed by means of hydrochloric acid, and the free
di-phenetidin citric acid is crystallized out from alcohol. Instead of employing
heat only, the reaction, mainly depending upon the separation of water, may, if
preferred, be effected by the addition of the well known water separating or
extracting agents. For the citric acid, an equivalent quantity of ether of citric
acid or chloride of citric acid may be substituted if desired. Where ether is used,
it is necessary to boil with soda lye the product of the reaction obtained
with para-amido-phenetol, so as to ensure the thorough saponification of all ether
groups.

page_text: Di-phentidin-citric acid is a white powder, dissolving in water with difficulty,
but more readily soluble in alcohol and sodium lye especially while being heated.
The sodium salt is soluble in water, but almost insoluble in alkaline solutions
The di-phenetidin-citric acid melts at 179° Centigrade.
The mono-phenetidin citric acid is a white crystalline powder containing water
of crystallization and melting at 72° Centigrade. It crystallizes out from
chloroform without water of crystallization and then has a melting point of
127° Centigrade.
It is readily soluble in cold water and still more readily in hot water.
Its taste
and reaction are acid, aud it dissolves with effervescence in a soda solution, and
while it does so, the sodium salt, readily soluble in water, is obtained, such salt
dissolving with far greater difficulty in a strong soda solution.
The mono- and di-phenetidin citric acid and their salts are medicinal substances
distinguishable by their energetic action as precipitants, by the absence of injurious
secondary reactions, and by the rapidity with which they act.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is :-
1. The manufacture of mono- and di-phenctidin citric acids consisting in
heating para-amido-phenetol with citric acid or chloride, or ether of citric acid,
with or without the addition of water extracting agents.
2. The new chemical compounds named mono-phenetidin citric acid and
di-phenetidin-citric acid, possessing the distinguishing qualities hereinbefore
described.
3. The new chemical compounds prepared by the process claimed by the first
preceding claiming clause and possessing the properties herein before indicated.
Dated this 18th day of January 1895.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.