Originator
Urokon Sodium ,Mallinckrodt Inc. ,US ,1950
Manufacturing Process
3-Amino-2,4,6-triiodobenzoic acid (51.5 g) was mixed with 125 ml of acetic
anhydride containing 2 drops of concentrated sulfuric acid and refluxed for
thirty minutes. The mixture was allowed to cool slightly, and then was poured
into 600 ml of water at room temperature and stirred until crystallization was
complete. The mixed anhydride of 3-acetylamino-2,4,6-triiodobenzoic acid
with acetic acid thus prepared was then separated by filtration and washed
with water. Without drying, the solid was suspended in 600 ml of water and
hydrolyzed with a slight excess of ammonium hydroxide. It was necessary to
warm the mixture slightly and stir it for about one-half hour in order to
dissolve all the solid. The solution was then treated with activated carbon,
filtered and precipitated with an excess of hydrochloric acid, filtered, washed
and dried at 70°C. The yield was 51.5 g of 3-acetylamino-2,4,6-triiodobenzoic acid which melted at 276.6-278.2°C with decomposition when placed in the
melting block at 260°C and heated at the rate of 3°C per minute. Due to
decomposition, the melting point varied from about 269-280°C, depending
upon the rate of heating and other conditions.
3-Acetylamino-2,4,6-triiodobenzoic acid (28 g) was dissolved in a little over
50 ml of 1 N sodium hydroxide in a round-bottom flask. The pH was adjusted
to slightly over 7 and the solution was evaporated on a steam bath under
reduced pressure. After the residue became solid, it was further dried
overnight in a vacuum desiccator containing calcium chloride. The salt
weighed 31.2 g, theory being 29.0 g, indicating that the product contains
about 7% water of crystallization when dried under these conditions. The
finished salt was scraped from the flask and ground.
Safety Profile
Mildly toxic by intravenous route.When heated to decomposition it emits very toxic fumes ofNOx, Na2O, and HI.
