| abstract |
(57) [Summary] [Object] To provide a method for industrially advantageously separating and purifying N-long chain acylamino acids of high quality and high purity. [Structure] A fatty acid halide having 6 to 22 carbon atoms is added to an aqueous amino acid solution in the presence of an alkali to cause a reaction, and the resulting synthetic reaction liquid of an N-long-chain acylamino acid alkali salt is adjusted to pH 1 to 5 with a mineral acid. Or a mixture of N-long-chain acylamino acid containing impurities such as an inorganic salt with water, and an organic layer containing an aqueous layer and an N-long-chain acylamino acid under the molten state of the N-long-chain acylamino acid. The layers are separated into layers, and then the N-long chain acylamino acid is obtained from the organic layer. |