α-Ketoamino acid ester 2-[2-(2-acetamidophenyl)-2-oxoacetamido] and 2-[4-(2-(2-acetamidophenyl)-2-oxoacetamido)benzamido] derivatives were synthesized via the ring opening of N-acetylisatin under mild conditions. These compounds were then examined for their capacity to inhibit monoamine oxidase (MAO). The inhibition profile was found to be competitive for compounds 4d, 6a, 6b and 6f, which showed MAO-A selectivity. Observation of the docked positions of these compounds revealed interactions with many residues previously reported to have an effect on the inhibition of the enzyme. Our findings indicate that the members of this family of α-ketoamino acid esters are promising MAO inhibitors.