Org. Synth. 1938, 18, 17
[Succinic acid, α,β-dibromo-]
Submitted by Herbert S. Rhinesmith
Checked by Reynold C. Fuson and W. E. Ross.
In a 2-l. three-necked, round-bottomed flask
, equipped with a mechanical stirrer (Note 1)
, dropping funnel
, and Friedrichs condenser1 (Note 2)
, are placed 200 g. (1.7 moles) of fumaric acid (Note 3)
and 400 g. of water (Note 4)
. The materials are thoroughly mixed until the fumaric acid
has been completely wet by the water. The resulting thick, viscous mass is then stirred vigorously (Note 5)
and brought to boiling by heating on a wire gauze
with a Bunsen flame (Note 6)
Two hundred and seventy-six grams (94.3 cc., 1.7 moles) of bromine (Note 7) is now added as rapidly as possible through the dropping funnel, the rate of addition being so controlled that the Friedrichs condenser is continuously about half full of the refluxing liquid (Note 8). This operation takes about one hour (Note 9). After about 100 g. of bromine has been added, the dibromosuccinic acid forms rapidly and separates in tiny white needles. At the completion of the reaction there should be a slight excess of bromine, as indicated by the red color of the solution. Occasionally 5–10 g. of bromine has to be added at this point to ensure an excess.
The reaction flask is now surrounded with ice water and cooled to 10°, with stirring. The product is then collected on a large Büchner funnel, and washed with cold water to remove the bromine liquor. The filtrate may be discarded, as it contains only impurities. The material is dried overnight at room temperature and need not be recrystallized; the yield is 343–400 g. (72–84 per cent of the theoretical amount).
A heavy stirrer with as large a paddle as possible is used, in order to rotate the mass of crystals formed during the course of the reaction. A mercury seal
is unnecessary, but it is advisable to have the stirrer bearing extend beneath the surface of the liquid.
Glass connections or rubber stoppers
should be used throughout, as corks
are rapidly disintegrated by the hot bromine
Commercial fumaric acid
("practical") is sufficiently pure for this preparation. Directions for preparing fumaric acid
are given on p. 302
Any larger amount of water leads to the formation of monobromomalic acid
, tartaric acid
, and compounds of unknown composition.2
Vigorous stirring is essential to obtain good yields.
It is necessary to keep the reaction mixture boiling throughout the entire course of the reaction. During the addition of the bromine
, however, the size of the flame should be reduced considerably, because the reaction is exothermic.
The apparatus should be set up under a hood
, or the top of the condenser connected to a gas absorption trap
for the removal of bromine
vapor, small amounts of which escape continually under the conditions of the experiment.
By this procedure most of the unchanged bromine
is washed back into the flask, so that the amount escaping from the top of the condenser is kept at a minimum.
If the bromine
is added over a much longer period of time, the yield is materially decreased.
may be prepared by heating succinic acid
and water in a closed tube at 180°;3
by heating succinic acid
, red phosphorus
, and bromine
in a closed tube at 140°;4
by heating fumaric acid
with 2 moles of bromine
in acetic acid
for seven hours in a sealed tube
from fumaric acid
, and water at 100° under pressure;6
and by the method described above.
This preparation is referenced from:
Chemical Abstracts Nomenclature (Collective Index Number);
acetic acid (64-19-7)
Succinic acid (110-15-6)
tartaric acid (87-69-4)
Fumaric acid (110-17-8)
Succinic acid, α,β-dibromo- (526-78-3)
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