Scheme 1. Synthetic route of GMI. Scheme 1 illustrates the process for preparing GMI. The synthesis of GMI followed the previously described method. In general, a mixture of maleic anhydride (0.1 mol, 9.8 g) in 50 mL of glacial acetic acid was combined with a solution of glycine (0.1 mol, 7.5 g) in 100 mL of glacial acetic acid. The mixture was stirred at room temperature and then filtered. The resulting precipitate was washed with cold water and dried under vacuum. Next, a suspension of N-glycinyl maleamic acid (16.8 mmol, 2.91 g) and Et3N (35.1 mmol, 3.55 g) in 500 mL of toluene was vigorously stirred and refluxed for 1.5 hours. During this time, a Dean-Stark apparatus was used to remove the byproduct water. The toluene solution was separated from the brown-colored oil and toluene was evaporated to obtain the triethylammonium salt. The resulting product was then acidified with HCl to pH 2 and extracted with ethyl acetate. The organic layer was dried with magnesium sulfate, and the ethyl acetate was evaporated to obtain GMI.