Manufacture of Derivatives of Ionone and Pseudo-ionone, and of B-ionone therefrom.
Year: 1898

page_text: Date of Application, 20th Apr., 1898
Complete Specification Left, 20th Jan., 1899-Accepted, 11th Mar., 1899
Manufacture of Derivatives of Ionone and Pseudo-ionone, and of
B-ionone therefrom.
I, JOHANN CARL WILHELM FERDINAND TIEMANN, of No. 4, Brueckenallée, Berlin, in
the Empire of Germany, Professor and Chemist, do hereby declare the nature of this
invention to be as follows:-
In the Specification No. 8736 of 1893 I have shewn that citral and acetone subjected
to the action of alkaline agents are condensed into an unsaturated aliphatic ketone of
the formula C3 H20 O called by me pseudo-ionone, and that when the same is treated
by acids, it is transformed into an isomeric ketone, ionone, which has a smell of
violets.
Ethyl acetyl-acetate (ethyl aceto-acetate) is the ethyl carboxylic derivative of
acetone.
It is therefore clear that citral and ethyl-aceto-acetate are capable of being condensed
into an ethyl-carboxylic derivative of pseudo-ionone, which derivative treated by
acids as set forth in Specifications No. 8736 of 1893 and 17539 of 1893 should form
an ethyl carboxylic derivative of ionone.
The experiments which have been made in this respect have not for a long time
given the anticipated result, because the aliphatic ethyl citralidene-aceto-acetate first
resulting form the condensation of citral with ethyl aceto-acetate is converted very
easily (for instance even by distillation at a reduced pressure) into a chemical
compound, the atoms or constituent parts of which are arranged in a manner entirely
differing from that of the atoms or constituent parts of the molecule of
ionone.
I have recently discovered that this transposition preventing the formation of
derivatives of ionone from aliphatic ethyl citralidene-aceto-acetate can be avoided if
this compound is converted, immediately after its production, into an ethylic salt of
ionone carboxylic acid by means of acids, care being taken that it does not get heated
to too high a temperature. It has been shewn in the Specification No. 23719 of 1897
that by treating pseudo-ionone by means of concentrated sulphuric acid at a
comparatively low temperature an ionone is obtained which contains a large amount
of that variety of ionone which is called 8-ionone or iso-ionone.
If the aliphatic eshyl citralidene-aceto-acetate is treated at a low temperature with
concentrated sulphuric acid it is turned into an ethylic salt of ionone-carboxylic acid
which like the ionone-carboxylic acid obtained therefrom by saponification, is derived
chiefly from 8-ionone or (iso-ionone). This ionone-carboxylic acid gives, when carbon
dioxide is eliminated from it, an ionone from which pure 8-ionone (iso-ionone) can
be easily obtained by the means set forth in the Specification No. 23719 of 1897.
The method hereinbefore described for producing the derivatives of pseudo-ionone
and ionone from ethyl aceto-acetate and citral as well as the preparation of the variety
of ionone known as ẞ-ionone (iso-ionone) are as follows;

page_text: The herein before described ionone-carboxylic acid is as already stated, chiefly derived
from the variety of ionone known as ẞ-ionone or iso-ionone. By heating the said ionone-
carboxylic acid in an atmosphere of carbon dioxide at the ordinary atmospheric
pressure up to and even a little above its melting point, carbon dioxide is eliminated
from the compound and an oily distillate is obtained which consists chiefly of
B-ionone.
If this oily distillate is dissolved in alcohol and to this solution an aqueous
solution of simicarbazide hydrochloride and sodium acetate is added, the semi-

page_text: carbazone of B-ionone is soon separated. From this semicarbazone ẞ-ionone is easily
separated by the process set forth in Specification No. 23719 of 1897.
1.1000
ABEL & IMRAY,
..Agents for the Applicant.
Manufacture of Derivatives of Ionone and Pseudo-ionone, and of
ẞ-ionone therefrom.
I, JOHANN CARL WILHELM FERDINAND TIEMANN, of No. 4, Brueckenallée, Berlin,
in the Empire of Germany, Professor and Chemist, 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 :-
:-
In the Specification No. 8736 of 1893 I have shewn that citral and acetone
subjected to the action of alkaline agents are condensed into an unsaturated aliphatic
ketone of the formula C1 H2O called by mne pseudo-ionone, and that when the same is
treated by acids, it is transformed into an isomeric ketone, ionone, which has a smell
of violets.
Ethyl acetyl-acetate (ethyl aceto-acetate) is the ethyl carboxylic derivative of
acetone.
It is therefore clear that citral and ethyl-aceto-acetate are capable of being
condensed into an ethyl-carboxylic derivative of pseudo-ionone, which derivative
treated by acids as set forth in Specifications No. 8736 of 1893 and 17539 of 1893
should form an ethyl carboxylic derivative of ionone.
The experiments which have been made in this respect have not for a long time
given the anticipated result, because the aliphatic ethyl citralidene-aceto-acetate
first resulting form the condensation of citral with ethyl aceto-acetate is converted
very easily (for instance even by distillation at a reduced pressure) into a chemical
compound, the atoms or constituent parts of which are arranged in a manner entirely
differing from that of the atoms or constituent parts of the molecule of ionone.
I have recently discovered that this transposition which prevents the formation of
derivatives of ionone from aliphatic ethyl citralidene-aceto-acetate can be avoided if
this compound is converted, immediately after its production, into an ethylic salt of
ionone carboxylic acid by means of acids, care being taken that it does not get heated
to too high a temperature. It has been shewn in the Specification No. 23719 of
1897 that by treating pseudo-ionone by means of concentrated sulphuric acid at a
comparatively low temperature an ionone is obtained which contains a large amount
of that variety of ionone which is called 8-ionone or iso-ionone.
If the aliphatic ethyl citralidene-aceto-acetate is treated at a low temperature with
concentrated sulphuric acid it is converted into an ethylic salt of ionone-carboxylic
acid which like the ionone-carboxylic acid obtained therefrom by saponification, is
derived chiefly from ẞ-ionone (or iso-ionone).
This ionone-carboxylic acid gives, when carbon dioxide is eliminated from it, an
ionone from which pure ẞ-ionone (iso-ionone) can be easily obtained by the means
set forth in the Specification No. 23719 of 1897.
The method herein before described for producing the derivatives of pseudo-ionone
and ionone from ethyl aceto-acetate and citral as well as the preparation of the
variety of ionone known as 8-ionone (iso-ionone) are as follows;

page_text: The aliphatic ethyl citralidine-aceto-acetate C₁H2O is obtained for instance
by heating for 5 or 6 hours in a steam bath a mixture consisting of :-
The herein before described ionone-carboxylic acid is as already stated chiefly
derived from the variety of ionone known as 8-ionone or isoionone. By heating the
said ionone-carboxylic acid in an atmosphere of carbon dioxide at the ordinary atmos-
pheric pressure up to and even a little above its melting point, carbon dioxide is
eliminated from the compound and an oily distillate is obtained which consists chiefly
of 8-ionone.
If this oily distillate is dissolved in alcohol and to this solution an aqueous solution
of semicarbazide hydrochloride and sodium acetate is added, the semicarbazone
of 8-ionone is soon separated. From this semicarbazone 8-ionone is easily isolated
by the process set forth in Specification No. 23,719 of 1897.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. Manufacture of aliphatic ethel citralidene-aceto-acetate (ethylic salt of pseudo-
ionone carboxylic acid) by heating together citral, ethyl aceto-acetate, acetic acid,
anhydrous sodium acetate and acetic anhydride in a steam bath and fractionally
distilling the product in a current of steam, substantially as described.
2. Manufacture of the ethylic salt of ionone carboxylic acid by treating aliphatic
ethyl citralidene aceto acetate with an acid, particularly sulphuric acid, substantially
as described.
3. Manufacture of ionone-carboxylic acid by treating aliphatic ethyl citralidene
aceto-acetate with an acid, particularly concentrated sulphuric acid, and saponifying
the ethylic salt of ionone-carboxylic acid thus produced, substantially as described.
4. Manufacture of ẞ-ionone (isoionone) by eliminating carbon dioxide from ionone-
carboxylic acid and treating the oily product thus obtained by the means described in
Specification No. 23,719 of 1897, in order to isolate the B-ionone, substantially as
described.
5. Aliphatic ethyl citralidene-aceto-acetate, ethylic salt of ionone carboxylic acid,
ionone carboxylic acid and B-ionone manufactured as herein set forth.
ABEL & IMRAY,
Agents for the Applicant.