Return to Abstracts of Patents

Return to Abstracts of Patents 500-749

Patent Abstracts

      650.  ------.  [FETTERLY, L. C.]  (Shell Development Co.)  Extractive Fractionation of Organic Compounds.  United States Patent 2,520,715, Aug. 29, 1950; appl. filed Mar. 29, 1947, Serial No. 738,213; 5 claims (Cl. 260-674).  United States Patent 2,520,716, Aug, 29, 1950; appl. filed Nov. 28, 1947, Serial No. 788,693; 10 claims (Cl. 260-676).  Chem. Zentralb., 1951, I, p. 2220.

            Organic compounds, which form crystalline complex compounds with urea or thiourea, are separated by fractionation.  The organic compounds are treated with urea or thiourea in presence of a selective solvent agent, which does not dissolve the complex compound.  According to another process, an acid anhydride (SO2, NO2, acetic anhydride), which forms a further complex compound with the original complex compound, is used in place of the solvent agent.  Example:  A mixture of normal and branched alcohols, containing an average of 10-14 C atoms obtained by the oxo synthesis, is treated with a concentrated solution of urea in liquid SO2 and the solid complex compound immediately separated:  this method, after separation and decomposition with H2O, yields the normal alcohols without the presence of isomers.