Novel synthesis of N-alkoxycarbonyl amino acids and surfactant properties of their sodium salts.

N-Acyl amino acids have been prepared from fatty acid chlorides and amino acids, but it may not be easy to vary the hydrophobic groups on the view point of availability. In this work, instead of acid halides, long alkyl chloroformates were prepared by the facile reaction of alcohols and triphosgene as an induction agent of hydrophobic group on amino acids. N-Alkoxycarbonyl amino acids were synthesized from alkyl chloroformate and amino acids under Schötten-Baumann reaction condition with some modification. Surfactant properties of their sodium salts were studied by surface tension measurements, dynamic light scattering and foaming test, and compared with those of N-acyl amino acids. Sodium salts of N-alkoxycarbonyl amino acids showed an excellent surface tension lowering ability comparable to N-acyl amino acids, and they also exhibited good foaming ability and stability.