PURPOSE: To rapidly, inexpensively and completely remove water that is produced continuously by dissolving an aminocarboxylic acid in an esterifying alcohol and allowing to react with the alcohol and evaporating produced water through a specified multi-layered membrane.
CONSTITUTION: An aminocarboxylic acid or N-terminal protected aminocarboxylic acid (preferably an aminocarboxylic acid protected with Z group) is dissolved in san esterifying alcohol or in other org. solvent (preferably THF or dioxane) and allowed to react with the alcohol. Water produced during the reaction is evaporated continuously through a multi-layered membrane consisting of a carrier having thickness of 50-300 μm, a porous main layer having thickness of 30-300 μm and a nonporous semipermeable membrane having thickness of 0.2-10 μm, to remove the water selectively from the reaction mixure. The multi-layered membrane is preferably a multi-layered membrane consisting of a polyester (non)woven fabric carrier, a polysulfone main layer and a semipermeable layer of a partly crystalline PVA. As a catalyst, p-toluenesulfonic acid is preferably used.
HARARUTO HERUMURITSUHI
HARARUTO ZUMAA
RAINAA NAADERERU
