(20b) Green Process Design for Synthesis of Sodium N-Lauroylglycinate to Replace the Traditional Schotten-Baumann Reaction

Abstract: With the development of green chemistry and increasing attention on the safety of chemicals, surfactants synthesized by petroleum base materials are gradually replaced by deriving from natural raw materials. N-fatty acyl amino acid sodium (SFAAA) is an industrialized anionic surfactant, which derived from natural fatty acids and industrial fermentation amino acids and has been widely applied in personal care and cleaning products due to its good surface activity and application performance, especially its low irritation, non-toxic and excellent biodegradability. However, the main synthesis method of N-fatty acyl amino acid sodium at present is via schotten-baumann reaction with fatty acyl chloride and amino acids as starting materials under the action of alkaline catalyst and bound acid agent. However, fatty acyl chloride is a non-natural ingredient, the aqueous solution increases the content of fatty acid sodium in the product and industrial three wastes generate after post-processing using the purification methods of acidification. In this paper, the synthesis of sodium N-lauroylglycinate avoids the problems existing in schotten-baumann reaction, with methyl laurate and sodium glycine as raw materials in methanol phase and sodium methoxide as catalyst which break the traditional synthesis methods was investigated, Sodium glycine would be recycled by a simple solid-liquid separation of  reaction product at room temperature and the target product would be obtained through simple process from the liquid phase. The synthesized N-lauroylglycinate was characterized by IR, MS and HPLC. The results indicate that the yield of N-lauroylglycinate reached 69.7% with the molar ratio of methyl laurate and sodium glycine 1.0:5.0, the dosage of sodium methoxide 1.2% compared with the total mass of reactants, anhydrous methanol as solvent and thermal water kettle as reactor at 135 ^oC for 12 h. This synthetic route provides apossibility for the alternative to traditional synthetic process.