Methods for preparation of propanone-1,3-disulfonic acid have been known for over thirty-five years, but these methods have a number of serious deficiencies.
An early reported method involved the reaction of acetone with dioxane-sulfur trioxide complex to yield acetone disulfonic acid, which was isolated as the barium salt, A. P. Terentev and L. A. Yanovskaya, Doklady Akad. Nauk. S.S.S.R., 75,235 (1950); Chem. Abstracts, 45,8445i (1951) Zh. Obshch. Khim., 23,618 (1953); Chem. Abstracts, 48,6958 (1954). This method has the disadvantage of requiring dioxane-sulfur trioxide, which is not commercially available on a large scale.
It was later reported that propanone-1,3-disulfonic acid could be prepared by the sulfonation of acetone with fuming sulfuric acid or oleum, W. Grot, J. Org. Chem., 30,515 (1965) and German Patent 70,392 issued Jun. 28, 1968 to F. Wolf. This method has the disadvantage of requiring one to separate the product from a large excess of sulfuric acid. Another difficulty is the preparation of oleum from sulfuric acid and sulfur trioxide, which is difficult to handle due to its narrow liquid range (boiling point 44.8 degrees Centigrade, freezing point 17 degrees Centigrade), and trace amounts of water act as a polymerization catalyst for liquid sulfur trioxide, producing polymers having elevated boiling points. In addition, oleum is not stable, and the sulfur trioxide sometimes separates as a lower layer which is difficult to re-dissolve.
In the same reference cited above, Grot also made reference to another method (no citation given) for the preparation of propanone-1,3-disulfonic acid from 1,3-dichloroacetone and alkali sulfites. This method would have the disadvantage of requiring expensive 1,3-dichloroacetone and would give the disodium or dipotassium salts rather than the free acid. The disodium or dipotassium salts are rather difficult to convert to the free acid. The procedure used for preparing the dipotassium salt was described earlier by F. Raschig and W. Prahl, Ber. der deutch. chem. Ges., 59B,2025 (1926).
U.S. Pat. No. 3,454,628 of G. Schroder et al discloses a method somewhat related to the Grot method described above. In the method of this patent acetone was reacted with fuming sulfuric acid in the presence of ammonium sulfate at 85 to 90 degrees Centigrade to directly prepare the diammonium salt of propanone-1,3-disulfonic acid. The free acid was not isolated from the salt, and this process also suffers from the same disadvantages as described above for the Grot process.
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