Process for the separation of isanic acid from boleko oil

摘要

Isanic acid of the formula CH2 = CH(CH2)4C ­ C-C ­ C(CH2)7 COOH is separated from boleko oil by dissolving the oil in an organic solvent, the concentration of the oil in the solution being from 10 to 33 per cent by weight, an alkali metal hydroxide in the solid state is allowed to act on this solution in the presence of water, the amount of alkali metal hydroxide added being between 1.0 and 1.4 times the theoretical amount calculated from the saponification number of the oil and the water content of the reaction mixture not exceeding 2 per cent by weight, the mixture is then cooled below 0 DEG C, preferably to -3 DEG C., the precipitate of insoluble alkali metal soaps is collected and the isanic acid is extracted therefrom by dissolving said soaps in water, adding a concentrated mineral acid, decanting the oily phase formed, extracting the aqueous phase with ether, adding the ethereal solution to the oily phase, evaporating the solvent, dissolving the residue in petroleum ether and crystallizing. The alkali metal hydroxide used in the above process may be sodium or potassium hydroxide, and the organic solvent may be acetone, ethyl alcohol or isopropyl alcohol. The reaction between the oil solution and the alkali-metal hydroxide is preferably carried out in a mixing apparatus, the rotating parts of which rotate at a high speed. A number of detailed examples are given.