N-Glyoxylamino acid ester derivatives were synthesized via the ring opening ofN-acetylisatin using moderate conditions. During the hydrazinolysis ofN-glyoxylamino acid ester derivatives with hydrazine hydrate (80%) in methanol, unexpected reduction of theα-keto group occurred to affordN-acylamino acid hydrazide derivatives in good yield (80–90%) (Wolff-Kishner type reaction). All the synthesized compounds were characterized by1H NMR,13C NMR, and elemental microanalysis.