Method to produce N-acyl amino acid surfactants using N-acyl amino acid surfactants or the corresponding anhydrides as catalysts

A process of producing N-acyl amino acid based surfactants of Formula I, wherein, R is selected from C6 to C22 alkyl group, R1 is selected from H, C1 to C4 alkyl, R2 is selected from all groups on α carbon of natural amino acids, R3 is selected from COOX, CH2-SO3X, X is selected from Li+, Na+ or K+. The process comprising steps of: A) preparing fatty acid chlorides by halogenating fatty acids with either phosgene or thionyl chloride in the presence of catalytic amount of same or other N-acyl amino acid surfactant of Formula I or anhydrides of same surfactant; and B) reacting fatty acid chloride of step (A) with an amino acid in the presence of a base.