Processes for Obtaining p-Phenetolcarbamide.
Year: 1892

page_text: Date of Application, 4th Nov., 1892-Accepted, 4th Feb., 1893
6
COMPLETE SPECIFICATION.
Processes for Obtaining p-Phenetolcarbamide.
I, HERMANN THOMS, Doctor of Philosophy, of 12/13 Gerichtstrasse, Berlin,
Germany, 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 :-
My previous researches (published in the Pharm. Centralhalle 1892, March 24)
have shown, that di-para-phenetylurea
\NHC¸H₂OC₂H¸
may be readily obtained, in addition to the hydro-chloride of phenetidin, by
causing carbonylchloride to act on a solution of p-phenetidin in toluene.
Since then I have found, that this body, when heated for several hours with
common urea CO:
NH,
NH,
in equimolecular proportions, in a closed space, and at
a temperature ranging between 150 and 160 degrees centigrade, is easily converted
into the p-phenetolcarbamide, as indicated by the following equation :
/NHC.H₂OC,H
NH,
NHCH₂OCH,
CO
+ CO
= 2 CO
NHC,H,OC,H
NH,
NH,
Instead of the common urea, the carbamide of ammonia, or commercial ammonium
carbonate, may be employed.
In the first case, the reaction takes place in the manner indicated by the following
equation:
NHCHOC,H,
NH,
CO
+ CO
NHC HOC,H
/NHCHOCH
ONH
= 2 CO
+ H₂O.
NH,
I have found also, that instead of the di-paraphenetylurca, the hydrochloride of
the p-phenetidin may be employed, the latter being either treated in a closed
retort with common urea or the carbamide of ammonia, or with commercial
ammonium carbonate, at a temperature of 160°, or an aqueous solution of the
hydrochloride of the p-phenetidin (3 molecules) and common urea (2 molecules)
being heated and kept at the boiling point for a considerable time. The reaction
takes place in the manner indicated by the following equation:
/NH,
NHC.N.OC,H,
/NHCH.OCH,
CO
+ CO
NH,
NHC HOCH¸
3 NH⭑Cl.
This process will yield, in addition to the para-phenetolcarbamide, also di-para-
henetylurea. The p-phenetolcarbamide crystallizes from the hot filtrate.
The para-phenetolcarbamide, obtained as described from di-para-phenetylurea,
Price 8d1

page_text: or from para-phenetidin-hydrochloride, by the action of common urea or the
carbamine salt of ammonia or commercial ammonium carbonate, and which is shortly
called "dulcin," melts at a temperature approaching 170°, and has a sweet taste of
extraordinary intensity, which renders it suitable for industrial application as a
sweetening substance. According to physiological experiments, the new substance
is quite harmless to the human organism.
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 I
claim is :-
:―
1. The process for obtaining para-phenetolcarbamide, which consists in heating
equimolecular quantities of di-para-phenetylurea or of para-phenetidinhydrochloride,
and common urea, or the carbamide of ammonia, or commercial ammonium-
carbonate, between 150° and 160°, for several hours in a closed retort, substantially
as described.
2. The process for obtaining para-phenetolcarbamide, which consists in boiling
an aqueous solution of para-phenetidinhydrochloride with common urea, in the
proportions of three molecules of the former to 2 molecules of the latter,
substantially as described.
Dated this 3rd day of November 1892.
FAIRFAX & WETTER,
433, Strand, London, Agents.