Manufacture of a New Lactone and of Phenylacetaldehyde therefrom.
Year: 1899

page_text: Manufacture of a New Lactone and of Phenylacetaldehyde
therefrom.
I, PROFESSOR DR. HUGO ERDMANN, of Alte Promenade 12, I, Halle a/S, in the
Empire of Germany, do hereby declare the nature of this invention to be as
follows:-
By the action of bromine and alkali on cinnamic acid Glaser (Liebig's Annalen
1868, CXXXXVII, 83) obtained, besides much resinous matter and bromo-styrole,
traces of a crystallised product which he found to contain bromine.
I have now found that the reaction leads to quite different results if cinnamic acid
is treated successively first with hypobromic acid (obtained from the solution of
bromine in alkali lye by the action of a weak acid, such as boric acid), and then with
alkali. Under these conditions no resinous matters and only traces of bromo-styrole
are formed, the cinnamic acid being converted into a new compound crystallising in
prisms, being free from bromine, melting at 83° to 84° C. and having the compo-
sition C,H,O,. The reaction by which this new compound is formed may be repre-
sented by the equation.
the new compound representing the ß-lactone of a-oxyphenylpropionic acid.
I have further found that by heating the new lactone, with or without addition of
water, phenylacetaldehyde is formed according to the following equation :
This reaction is very convenient for the technical production of phenylacetalde-
hyde, which is valuable as a perfume but can only be obtained with very bad yield
5 by the methods hitherto known for its preparation.
In order to further illustrate my invention and how it can be carried out, I give the
following examples. The parts are by weight,

page_text: A. PRODUCTION OF THE B-LACTONE OF α-OXYPHENYLPROPIONIC ACID.
150 parts of cinnamic acid are dissolved in 1500 parts of water with addition of
108 parts of potash lye of 50% KOH and the solution is evaporated until its volume
is reduced to about its third, whereupon the whole is stirred until cold. To the mix-
ture are then added 1500 parts of crushed ice and 200 parts of crystallised boric acid,
whereupon is immediately added the bromine lye which had been prepared as
follows:-
308 parts of potash lye of 50% KOH, free from carbonic acid are mixed with 200
parts of crushed ice. 220 parts of bromine are allowed to flow into the lye, while
constantly stirring, and cooling well. Finally 31 parts of potash lye of 50% KOH
are stirred into the liquor in order to be sure that no more free bromine is contained
therein.
On addition of the so prepared bromine lye to the above mixture of potassium
cinnimate and boric acid, a nearly clear solution is produced, only part of the ice and
some boric acid remaining undissolved. The liquid, even after standing for some
time, should show strong bleaching power, decolorising for instance litmus paper.
616 parts of potash lye of 50% KOH are now added by portions in the course of an
hour. At first only a milky turbidness is produced, but soon the potassium salt of the
B-lactone and a-oxyphenylpropionic acid,
separates in the form of a thick white precipitate. After standing for 4 to 6 hours
the precipitate is filtered off and washed with 80 parts of alcohol and afterwards with
80 parts of ether.
The potassium salt thus obtained may be further purified by extracting it with
ether or by converting it into a less soluble salt, containing only half the quantity of
potassium. This salt, the composition of which is represented by the formula :
CgHgOg + C,H,O,K + 2 H,O.
is obtained in the form of a crystalline precipitate by adding to the aqueous solution
of the raw potassium salt, produced as above shown, half the equivalent quantity of
mineral acid.
In order to obtain the free oxy-lactone, the calculated quantity of diluted sulphuric
acid is added at 0° C. to the aqueous solution or suspension of one of its alkali
salts.
The lactone at once separates in the form of a colourless oil, which soon becomes
solid. It melts at 83° to 84° C.
The B-lactone of a-oxyphenyl-propionic acid is little soluble in water and possesses
like other oxylactones (compare Knorr, Liebigs Annalen 1898, CCCIII, 138) feebly
acid reaction. Its alkali salts are easily decomposed, they are soluble in water,
alcohol and especially in freshly precipitated state, also in ether.
They are insoluble in alkali lyes and solutions of common salt.
The new lactone is decomposed by heating it in or without the presence of water,
carbonic acid being split off.
Instead of the bromine lye, hypochlorites can be used for the production of the
new lactone, the yields however are much less satisfactory in this case.
B. PRODUCTION OF PHENYLACETALDEHYDE FROM THE B-LACTONE OF a-OXYPHENYL-
PROPIONIC ACID.
1. Dry ß-lactone of a-oxyphenylpropionic acid is heated in a vessel evacuated by
means of a well acting air pump, care being taken not to let the pressure inside the
vessel rise above 160 millimeters in spite of the carbonic acid devoloped by the
melting lactone. After the pressure is again reduced to 12 millimeters, pure

page_text: phenylacetaldehyde distils over at 80° C. and can be condensed and collected in a
suitable apparatus. It forms a colourless liquid; boiling at 78° C. under 11 milli-
meters pressure.
2. 100 parts of the ß-lactone are mixed with 1000 parts of water and a current of
5 steam is passed through the liquid. Phenylacetaldehyde distils over the water. It
is then separated from the latter and redistilled in vacuo.
3. 60 parts of the potassium salt of the B-lactone represented by the formula:
are dissolved in 200 parts of warm water. A solution of 50 parts of tartaric acid in
100 parts of water is then added and the phenylacetaldehyde is distilled over by
means of a current of steam. It is thereupon separated and redistilled in vacuo.
The quantity of tartaric acid above indicated being sufficient for converting all the
potassium contained in the compound C₂H,O₂K + 3 H2O into acid potassium tartrate,
only tartar remains in residue, being separated already in the heat as a white crystal-
line powder.
4. Three parts of the less soluble potassium salt of the ß-lactone :
ABEL & IMRAY,
Agents for the Applicant.
Manufacture of a New Lactone and of Phenylacetaldehyde
therefrom.
I, PROFESSOR DR. HUGO ERDMANN, of Alte Promenade, 12, I, Halle a/S, in the
Empire of 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 :-
By the action of bromine and alkali on cinnamic acid Glaser (Liebig's Annalen
1868, CXXXXVII, 83) obtained, besides much resinous matter and bromo-styrole,
traces of a crystallised product which he found to contain bromine.
I have now found that the reaction leads to quite different results if cinnamic acid
is treated successively first with hypobromic acid (obtained from the solution of
bromine in alkali lye by the action of a weak acid, such as boric acid), and then with
alkali.
Under these conditions no resinous matters and only traces of bromo-styrole are
formed, the cinnamic acid being converted into a new compound crystallising in
prisms, being free from bromine, melting at 83° to 84° C. and having the com-

page_text: position CHO₁. The reaction by which this new compound is formed may be
represented by the equation
the new compound representing the ß-lactone of a-oxyphenylpropionic acid.
I have further found that by heating the new lactone, with or without addition of
water, phenylacetaldehyde is formed according to the following equation:
This reaction is very convenient for the technical production of phenylacetalde-
hyde, which is valuable as a perfume but can only be obtained with very bad yield
by the methods hitherto known for its preparation.
In order to further illustrate my invention and how it can be carried out, I give
the following examples. The parts are by weight.
A. PRODUCTION OF THE ẞ-LACTONE OF a-OXYPHENYLPROPIONIC ACID.
150 parts of cinnamic acid are dissolved in 1500 parts of water with addition of
108 parts of potash lye of 50% KOH and the solution is evaporated until its volume
is reduced to about its third, whereupon the whole is stirred until cold. To the
mixture are then added 1500 parts of crushed ice and 200 parts of crystallised boric
acid, whereupon is immediately added the bromine lye which had been prepared as
follows:-
:-
308 parts of potash lye of 50% KOH, free from carbonic acid are mixed with
200 parts of crushed ice. 220 parts of bromine are allowed to flow into the lye, while
constantly stirring, and cooling well. Finally 31 parts of potash lye of 50% KOH
are stirred into the liquor in order to be sure that no more free bromine is contained
therein.
On addition of the so prepared bromine lye to the above mixture of potassium
cinnamate and boric acid, a nearly clear solution produced, only part of the ice and
some boric acid remaining undissolved. The liquid, even after standing for some
time, should shew strong bleaching power, decolorising for instance litmus paper.
616 parts of potash lye of 50% KOH are now added by portions in the course of an
At first only a milky turbidness is produced, but soon the potassium salt of
the 8-lactone of a-oxyphenylpropionic acid,
hour.

page_text: the precipitate is filtered off and washed with 80 parts of alcohol and afterwards
with 80 parts of ether.
The potassium salt thus obtained may be further purified by extracting it with
ether or converting it into a less soluble salt, containing only half the quantity
of potassium. This salt, the composition of which is represented by the
formula:-
s obtained in the form of a crystalline precipitate by adding to the aqueous
solution of the raw potassium salt, produced as above shewn, half the equivalent
quantity of mineral acid.
In order to obtain the free oxy-lactone, the calculated quantity of diluted sulphuric
acid is added at 0°C. to the aqueous solution or suspension of one of its alkali
salts.
The lactone at once separates in the form of a colourless oil, which soon becomes
solid.
It melts at 83° to 84° C.
The ß-lactone of a-oxyphenylpropionic acid is little soluble in water and possesses
like other oxylactones (compare Knorr, Liebig's Annalen 1898, CCC III, 138) feebly
acid reaction. Its alkali salts are easily decomposed, they are soluble in water, alcohol
and especially in freshly precipitated state also in ether.
They are insoluble in alkali lyes and solutions of common salt.
The new lactone is decomposed by heating it in or without the presence of water,
carbonic acid being split off.
Instead of the bromine lye, hypochlorites can be used for the production of the
new lactone, the yields however are much less satisfactory in this case.
B. Production of phenylacetaldehyde from the ß-lactone of a-oxyphenylpropionic
acid.
1. Dry ß-lactone of a-oxyphenylpropionic acid is heated in a vessel evacuated by
means of a well acting air pump, care being taken not to let the pressure inside the
vessel rise above 160 millimeters in spite of the carbonic acid developed by the
melting lactone. After the pressure is again reduced to 12 millimeters, pure
phenylacetaldehyde distils over at 80° C. and can be condensed and collected in a
suitable apparatus. It forms a colourless liquid, boiling at 78° C. under 11 millimeters
pressure.
2. 100 parts of the ß-lactone are mixed with 1000 parts of water and a current of
steam is passed through the liquid.
Phenylactaldehyde distils over with the water.
and redistilled in vacuo.
It is then separated from the latter
3. 60 parts of the potassium salt of the ß-lactone represented by the formula:
are dissolved in 200 parts of warm water. A solution of 50 parts of tartaric acid
in 100 parts of water is then added and the phenylacetaldehyde is distilled over
by means of a current of steam. It is thereupon separated and redistilled
in vacuo.
The quantity of tartaric acid above indicated being sufficient for converting all the
mound

page_text: into acid potassium tartrate, only tartar remains in residue, being separated already
in the heat as a white crystalline powder.
4. Three parts of the less soluble potassium salt of the ß-lactone :
are suspended in 10 parts of water, a solution of 1 part of oxalic acid in 5 parts of water
is added and the phenylacetaldehyde is distilled off by means of steam. Acid oxalate
of potassium remains in residue.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I
claim is -
1. The herein described manufacture of the ß-lactone of a-oxyphenylpropionic
acid by treating cinnamic acid first with hypobromic acid and then with alkali.
2. The B-lactone of a-oxyphenylpropionic acid manufactured as above set forth.
3. Production of phenylacetaldehyde by heating theß-lactone of a-oxyphenylpro-
pionic acid with or without water.
Duted this 1st day of January 1000
ABEL & IMRAY,
Agents for the Applicant.