Method for concentrating aqueous 3-hydroxy-2,2-dimethylpropanal solution

摘要

The present invention provides a method for concentrating an aqueous solution containing at least 3-hydroxy-2,2-dimethyl propanal and/or a dimer thereof, which includes subjecting a mixed solution of an aqueous solution containing at least 3-hydroxy-2,2-dimethyl propanal and/or a dimer thereof and an azeotropic agent to azeotropic distillation in a distillation column to distil off water and the azeotropic agent from the mixed solution, wherein the mixed solution is prepared by adding, as the azeotropic agent, at least one selected from the group consisting of 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-pentanol and 1-hexanol to the aqueous solution.