Process for Obtaining Para-phenetolcarbamide.
Year: 1893

page_text: Date of Application, 2nd June, 1893
Complete Specification Left, 16th Feb., 1894-Accepted, 17th Mar.. 1894
PROVISIONAL SPECIFICATION.
Process for Obtaining Para-phenetolcarbamide.
I, JASPER WETTER, Patent Agent, of 433 Strand, in the County of London,
do hereby declare the nature of this invention, a communication from the Firm of
J. D. Riedel, Manufacturing Chemists, of Gerichtstrasse, Berlin, in the German
Empire, to be as follows:-
If an aqueous solution of p-phenetidin-hydrochloride (3 molecules) is heated
with ordinary urea (2 molecules) according to a process previously discovered by
my correspondents, p-phenetol-carbamide and diparaphenetol-carbamide are
produced, as indicated by the following equation :-
Since then my correspondents have found, that the formation of the dipara-
phenetol-carbamide may be entirely avoided, or that it may be immediately con-
verted into paraphenetol carbamide, if para-phenetidin is heated (to the boiling
point) with nitrate of urea or with another urea salt, in aqueous solution for
several hours, by means of a reflux cooler, and in the proportion of one molecule
of the para-phenetidin to at least one molecule of the urea salt, whereby the whole
of the p-phenetidin is transformed into p-phenetol carbamide.
The p-phenetol-carbamide is eliminated in the shape of colourless crystals,
already during the boiling in the retort, while the nitrate of ammonia produced
remains in the aqueous solution. It is advisable, to employ a large excess of
nitrate of urea. The heating (boiling) is continued, until there remains no longer
any phenetidin in the liquid (as far as can be ascertained by ordinary tests).
The course of this action is less advantageous, if phenetidin is directly heated
with nitrate of urea to 140 to 150 degrees C., the nitrate of urea being slowly
added.
EXAMPLE.
After
1000 grammes of para-phenetidin were heated with 2000 grammes of nitrate of
urea and 5000 grammes of water for 6 hours, by means of a reflux cooler.
cooling and filtration, there were obtained 700 grammes of the crystallized
p-phenetol-carbamide; the mother liquor was further heated on the reflux cooler
for about 4 hours, and thereby again 600 grammes of phenetol-carbamide,
obtained.
Dated this Second day of June 1893
FAIRFAX & WETTER,
Agents for the Applicant.

page_text: Process for Obtaining Para-phonetolcarbamide.
I, JASPER WETTER, Patent Agent, of 433 Strand, in the County of London,
do hereby declare the nature of this invention and in what manner the same is to
be performed, a communication from the Firm of J. D. Riedel, Manufacturing
Chemists, of Gerichtstrasse, Berlin, in the German Empire, to be particularly
described and ascertained in and by the following statement:-
The methods hitherto known for the production of p-phenetol-carbamide have
the drawback, that they never yield the theoretical quantity, owing to the secondary
interactions, with which they are attended.
It is evident, therefore, that a process which converts the whole of the phenetidin
into p-phenetol-carbamide without any loss through the formation of bye-products,
would offer a great advantage.
My correspondents have found, that this is the case with the manufacture of
p-phenetol-carbamide from p-phenetidin and nitrate of urea, or from hydrochloride
of p-phenetidin and free urea, as hereafter described.
If para-phenetidin is heated (to the boiling point) with nitrate of urea in
aqueous solution for several hours, by means of a redux cooler, the whole of the
phenetidin may be transformed into phenetol-carbamide.
The
The latter is eliminated in the shape of colourless crystals, already during the
boiling in the retort, while the nitrate of ammonia produced remains in the aqueous
solution. It is advisable, to employ a large excess of nitrate of urea.
heating (boiling) is continued, until there remains no longer any phenetidin in the
liquid. Instead of the nitrate, other urea salts may be employed.
The course of this reaction is less advantageous, if phenetidin is directly heated
with nitrate of urea to 140 to 150 degrees C., the nitrate of urea being slowly
added to the phenetidin.
EXAMPLE.
1000 grammes of para-phenetidin were heated with 2000 grammes of nitrate of
urea and 56.00 grammes of water for 6 home humanne
FAIRFAX & WETTER,
433, Strand, London, Agents.