2513. ---------------.  [OHME, W.]  Conversion of Fat Acids From the Fischer-Tropsch Synthesis to Ketones. Oel u. Kohle Erdoel Teer, vol. 40, 1944, pp. 87-89; Ind. Chemist, vol. 21, 1945, pp. 270-274; Chem. Abs., vol. 39, 1945, p. 277.

    Fat acids formed as byproducts in the Fischer-Tropsch synthesis were obtained by extracting certain hydrocarbon fractions with caustic and acidifying the solution.  Part of the fat acids was distilled at 0.5 mm. Hg and another part was directly converted into the Ca salts by reaction with an excess of lime.  The Ca salts were subjected to dry distillation at 350°-650°, and the ketones formed were distilled at atmospheric pressure and redistilled under vacuum.  The bulk of the ketones boiled 240°-300°, and the melting point varied from –10° to +30°; it is assumed that mixed ketones with 12-17 C atoms have been formed.  The fractions obtained by distillation of the original fat acids represent C₅, C₆, C₁₀, C₁₁, C₁₂, C₁₅, and C₁₈ fat acids.  Each fraction was individually converted into the corresponding ketones at temperatures ranging 280°-600°, and the average yield amounted to 70-80%.  The ketones were not uniform, as indicated by their rather wide boiling range (50°-70°).  The melting point of the ketones increases with the number of C atoms from –50° to –62° for C₅ ketones, over –10° to +20° for the C₁₁ ketones, and to 32°-44° for the C₁₅ ketones.  The ketones are partly liquids of agreeable odor and partly waxlike substances; they might find use as plasticizers and in the perfume industry.