Synthesis of new compounds derived from metronidazole and amino acids and their esters as antiparasitic agents

A number of new compounds derived from metronidazole and amino acids and their esters have been synthesized through a reaction between 2-(2-methyl-5-nitro-1 H -imidazol-1-yl)acetic acid and a number of amino acid esters in the presence of N , N ′carbonyldiimidazole (CDI). Hydrolysis of the esters derivatives with sodium hydroxide (4%) followed by acidification with hydrochloric acid (3 M) afforded the corresponding acids. The newly synthesized compounds were characterized by elemental analysis and by spectroscopic techniques such as 1 H-NMR, 13 C-NMR, and mass spectrometry. Some of the prepared compounds exhibited lethal activity against pathogenic protozoan parasites.