| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an L-ascorbic acid tetracarboxylic acid ester high in purity, good in initial hue and excellent in hue stability with time. SOLUTION: The method for producing the L-ascorbic acid tetracarboxylic acid ester by esterification reaction between L-ascorbic acid and a carboxylic acid halide is provided, comprising a first esterification step of conducting a 25-75% esterification in the presence of a basic solvent at 4-5 mol per mole of the L-ascorbic acid and a second esterification step of conducting a further esterification by adding a nonpolar solvent at 0.25-10 pts.mass per part mass of the L-ascorbic acid. COPYRIGHT: (C)2008,JPO&INPIT
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