Org. Synth. 1953, 33, 41
Submitted by Henry Feuer and Stanley M. Pier1
Checked by William S. Johnson and Ernest F. Silversmith.
In a 500-ml. round-bottomed flask
fitted with a reflux condenser
and a drying tube leading to a gas-absorption trap2
are placed 234 g. (1.1 mole) of phosphorus pentachloride (Note 1)
and 65 g. (0.5 mole) of itaconic acid (Note 2)
. The reagents are mixed by shaking the flask; after a few minutes a vigorous reaction commences, resulting in partial liquefaction of the mixture and copious evolution of hydrogen chloride
. When the initial reaction subsides, the mixture is gently heated to cause reflux of phosphorus oxychloride
until all the solid dissolves; then heating is continued for an additional 15 minutes (Note 3)
. The reflux condenser
is replaced by a 12-in. Vigreux column
, and the phosphorus oxychloride
is removed by distillation at reduced pressure provided by a water aspirator (Note 4)
, the major portion coming over at about 45°/85 mm. When all the phosphorus oxychloride
has been removed, the pressure is reduced (vacuum pump
) and the material boiling at 70–75°/2 mm.
is collected. Liquid boiling in this range weighs 50–55 g.
, representing a yield of 60–66%.
This material, nD20
1.4900, is pure enough for most purposes, but it may be further refined by distillation through a packed column, yielding 47–53 g.
of a water-white liquid, nD20
1.4919, boiling at 71–72°/2 mm.
The slight molar excess of phosphorus pentachloride
has been found to increase the yield of product. It is best to use apparatus with ground-glass joints.
Chas. Pfizer and Company technical grade itaconic acid
was employed without purification.3
Heating for a longer period results in a rather sudden change in color from pale yellow to deep orange or red, and a decrease in yield.
Considerable dissolved hydrogen chloride
is liberated at this point and passes into the water aspirator
. A mechanical vacuum pump should not be used at this stage because it would be damaged by corrosion.
has been prepared previously only by the reaction of itaconic anhydride
with phosphorus pentachloride
Chemical Abstracts Nomenclature (Collective Index Number);
hydrogen chloride (7647-01-0)
phosphorus pentachloride (10026-13-8)
Phosphorus Oxychloride (21295-50-1)
Itaconic anhydride (2170-03-8)
Itaconic acid (97-65-4)
Itaconyl chloride (1931-60-8)
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