Patent ID: 6072083
Filing Date: 2000-06-06
Classification: C07C

Abstract:
A method for purifying valine, leucine and isoleucine, comprising:in the same purification facility,(1) contacting p-ethylbenzenesulfonic acid or a water-soluble salt thereof with an aqueous solution of valine to precipitate crystals of valine p-ethylbenzenesulfonate, and then separating and decomposing said crystals to obtain valine;(2) contacting p-ethylbenzenesulfonic acid or a water-soluble salt thereof with an aqueous solution of leucine to precipitate crystals of leucine p-ethylbenzenesulfonate, and then separating and decomposing said crystals to obtain leucine; and(3) contacting p-ethylbenzenesulfonic acid or a water-soluble salt thereof with an aqueous solution of isoleucine to precipitate crystals of isoleucine p-ethylbenzenesulfonate, and then separating and decomposing said crystals to obtain isoleucine.