Synthesis and Identification of New 2-Substituted-1,3,4-Oxadiazole Compounds from Creatinine and Study Their Antioxidant Activities

The synthesis of many new 2-substituted 1,3,4-oxadiazoles from creatinine is studied in this research. The ester of creatinine 1a was formed by the reaction of creatinine with ethylchloroacetate, and then with two of alkyl halides to produce compounds 2a-2b. Following that, hydrazide derivatives 3a-3b were produced by compounds 2a-2b with semicarbazide hydrochloride. These hydrazides were cyclized with 5 percent sodium hydroxide to produce 1,3,4-oxadiazole derivatives 4a-4b. The reaction of these compounds with aromatic aldehydes produced Schiff bases 5a-5d. Finally, diazetidine 6a-6h and β-lactam 7a-7d derivatives on position (2) from 1,3,4-oxadiazole were formed by reacting Schiff bases with various reagents. FT-IR spectroscopy and 1H-NMR for some synthesized compounds were used to identify the newly synthesized compounds. In vitro, antioxidant activities of some synthesized compounds were also investigated with promising results.