A process for preparing phenol sulfonate esters of hydrocarboyl amino acids, comprising the steps of:(a) reacting an amino acid of the formula ##STR4## wherein n is from 1 to about 8, M is H or an alkali metal salt, and R is a C1 -C14 alkyl, alkenyl, aryl or alkaryl substituent, with an acid halide to prepare the corresponding amino acid halide; and (b) reacting the amino acid halide of step (a) w