Eight N-substituted diketopiperazines (DKPs) were synthesized by solid-phase protocols. The introduction of iminodiacetic acid (Ida) and followed another α-amino acid residue as the precursor of DKP framework made the present synthesis to be very facile and efficient. The introduction of iminodiacetic acid (Ida) and subsequently another α-amino acid residue as the precursor of DKP framework made the present synthesis to be very facile and efficient.