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

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.