Org. Synth. 1928, 8, 54
[Propionic acid, β-chloro-]
[(A) (from Acrolein)]
Submitted by C. Moureu and R. Chaux.
Checked by C. S. Marvel and L. F. Martin.
In a tared Erlenmeyer flask
surrounded by an ice-salt bath
is placed 100 g. (119 cc., 1.78 moles) of acrolein (p. 15) (Note 1)
. When the temperature has dropped to −10 to −15° a current of dry hydrogen chloride (p. 293)
is passed into the acrolein
until it shows a gain in weight of 65 g.(1.78 moles). This requires about two hours. The product thus obtained is a clear, viscous, slightly yellow liquid which becomes very turbid and dark colored on standing one or two days (Note 2)
The oxidation of the crude β-chloropropionaldehyde is carried out in a 200-cc. flask fitted with a cork stopper held about 2 cm. above the opening of the neck by means of a clamp. The stopper carries a mechanical stirrer, a separatory funnel, a thermometer, and a glass delivery tube about 10 mm. in diameter which is connected to a water pump. The space between the stopper and the flask is closed by winding a strip of asbestos paper around it (Note 3).
In the flask is placed 64 g. (43 cc., 0.9 mole) of fuming nitric acid (sp. gr. 1.49) (Note 4), the stirrer is started, and about one-sixth (Note 5) of the crude β-chloropropionaldehyde is added (Note 6) very slowly through the separatory funnel. About 1 cc. of the aldehyde is added to the acid. The temperature remains constant for one or two minutes and then slowly rises. As the oxidation begins, oxides of nitrogen are evolved and are drawn off by means of the water pump. When the temperature of the reaction mixture reaches about 30° (Note 7), the flask is immersed in a water bath (at 15–20°) and the rate of addition of the aldehyde is regulated so that the temperature of the reaction mixture is 30–35°. After the addition of the last portion of the aldehyde, stirring is continued until the temperature drops below 25°. This oxidation requires about twenty-five minutes.
The products of six successive oxidations are combined in a 1-l. long-necked flask. Oxides of nitrogen are evolved but there is no danger of a violent reaction. The entire quantity of liquid is heated gradually on a water bath until the bath is boiling. This should be done under a hood as large quantities of oxides of nitrogen are evolved (Note 8). After about one and one-half hours the oxidation is complete and a yellow-brown liquid remains.
The liquid is placed in a modified Claisen flask (p. 130)
and distilled (Note 9)
from an oil bath
with a water pump, care being taken to protect the manometer
(placed in shunt in order to avoid the passage of a current of vapors) by a tube containing solid sodium hydroxide
. A water condenser 40–50 cm. long
should be used. At first oxides of nitrogen
are evolved and it is difficult to obtain a low pressure. Then the pressure drops (to about 20–25 mm.) and nitric acid
distils at 40–70°. When the distillation has nearly stopped, the temperature of the bath is raised until the boiling point of the distilling vapors reaches 100°. This fraction weighs 160–170 g. and is nitric acid
having a specific gravity of 1.25–1.30. It may contain a small amount of acrylic acid
. The condenser is now removed from the apparatus, a distilling flask
attached as receiver
, and the residue is fractionated at 20 mm., collecting about 4–5 g. boiling up to 105°, and 116–125 g.
of β-chloropropionic acid
boiling at 105–107°
per cent of the theoretical amount). The product melts at 35–40°
(purest acid melts at 42°
). The fraction boiling below 105° contains a large proportion of β-chloropropionic acid
and should be redistilled with a subsequent run.
used by the checker was obtained by distilling the commercial material (stabilized by hydroquinone
) purchased from Poulenc Frères. Acrolein
has pronounced lachrymatory properties and is also highly toxic.
is a very unstable substance which polymerizes rapidly, especially in the presence of traces of hydrochloric acid
. The crude material must be oxidized without delay as standing before oxidation will cause a lowering of the yield.
This constitutes a safety device
, since it prevents diffusion of the oxides of nitrogen
, but in case the reaction becomes violent it permits a free expansion of a sudden surge of gases.
The concentration and purity of the fuming nitric acid
are of considerable importance. It should have a specific gravity of not less than 1.49 and should leave no residue on distillation.
It is not advantageous to work with larger quantities as an explosive reaction is likely to occur if stirring is stopped.
It is absolutely necessary to introduce the aldehyde
into the nitric acid
. When the reverse is attempted the reaction starts slowly but soon becomes explosive.
The temperature interval most favorable for the reaction is 30–35°.
The reaction mixture may also be worked up by pouring it into water and extracting the β-chloropropionic acid
. This is less satisfactory as the nitric acid
is lost and some of the β-chloropropionic acid
remains in the water.
[(B) (from Trimethylene Chlorohydrin)]
Submitted by S. G. Powell, E. H. Huntress, and E. B. Hershberg.
Checked by L. F. Fieser and A. M. Seligman.
A 3-l. long-necked Pyrex flask
containing 880 g. (620 cc., 10 moles) of concentrated nitric acid
(sp. gr. 1.42) is supported in an ice bath
in a hood
and supplied with a mechanical stirrer
and a thermometer
suspended in the liquid. While the temperature is kept between 25° and 30° by means of the ice bath, 200 g. (2.12 moles) of trimethylene chlorohydrin (p. 533)
is run in from a dropping funnel (Note 1)
. The addition takes two to three hours. Stirring is continued for a half hour longer.
The reaction mixture is allowed to stand overnight and is then heated for one hour on the steam bath
. It is transferred to a modified Claisen flask (p. 130)
, and the β-chloropropionic acid
is isolated by distillation under reduced pressure, employing a water pump
. Nitric acid
is collected up to 100°/20 mm., using a water condenser (Note 2)
. The condenser is replaced by a distilling flask
, and the residual material is fractionated. The yield of β-chloropropionic acid
boiling at 107–109°/20 mm.
and freezing at 39°
is 179–181 g.
per cent of the theoretical amount).
There is sometimes difficulty in starting the reaction using pure nitric acid
. Once started, the oxidation proceeds rapidly under the catalytic influence of the oxides of nitrogen
formed. The checkers found it convenient, in order to start the reaction, to oxidize a few drops of the chlorohydrin
with nitric acid
by heating in a test tube
and to add this to the nitric acid
in the flask without stirring. A small portion of the chlorohydrin
is then added and allowed to react for a few minutes before starting the stirrer and continuing the oxidation of the main lot.
About 500 cc. of nitric acid
(sp. gr. 1.27) is obtained. If desired the oxidation mixture may be diluted with water and the β-chloropropionic acid
extracted with ether
and distilled. Some material is lost in the water by this procedure.
can be prepared by the hydrolysis of ethylene cyanohydrin
with hydrochloric acid
by the oxidation of β-chloropropionaldehyde
with nitric acid
by the oxidation of trimethylenechlorohydrin
with nitric acid3
and by hydrolysis of the condensation product of phosgene
Chemical Abstracts Nomenclature (Collective Index Number);
oxides of nitrogen
hydrochloric acid (7647-01-0)
sodium hydroxide (1310-73-2)
nitric acid (7697-37-2)
Ethylene cyanohydrin (109-78-4)
Acrylic acid (9003-01-4)
Propionic acid, β-chloro- (107-94-8)
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