Oxindole-3-propionic acid has been obtained by reduction of the condensation product of oxindole and ethyl malonate. In the course of this series of reactions, interesting intermediates for the synthesis of dioxindole-3-alanine have been secured. Of the two products formerly described in the literature, only that of Kendall is authentic oxindole-3- propionic acid. Previ-ous attempts to prepare oxindole-3-propionic acids by Michael ...
