SEPARATION OF HYDROXYPIVALIC ACID FROM ITS AQUEOUS SOLUTION

PROBLEM TO BE SOLVED: To separate hydroxypivalic acid from its aqueous solution by azeotropic distillation by the use of organic solvents under reduced pressure. SOLUTION: This separation of hydroxypivalic acid from its aqueous solution comprises removing water by azeotropic distillation by using polar and nonpolar solvent mixture under reduced pressure at a maximum bottom temperature of 90 deg.C in a distillation column until the water content of the obtained solution of hydroxypivalic acid decreases to at least 0.1wt.% based on the total weight, and subsequently recrystallizing hydroxypivalic acid from the solvent mixture.