Into a 100-mL round-bottom flask, was placed a mixture of methyl 5-(2-bromopropanoyl)-2,4-dimethylbenzoate (compound 1.6, 600 mg, 2.01 mmol), 2-methoxyethanimidamide hydrochloride (510 mg, 4.09 mmol), potassium carbonate (840 mg, 6.08 mmol) and acetonitrile (30 mL). The resulting mixture was stirred at 80° C. overnight, then cooled to room temperature and concentrated under reduced pressure. The residue was diluted with H2O (50 mL) and extracted with ethyl acetate (100 mL). The organics was washed brine (2×50 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography with ethyl acetate/petroleum ether (1:2) as the eluent to yield methyl 5-(2-(methoxymethyl)-4-methyl-1H-imidazol-5-yl)-2,4-dimethylbenzoate (compound 2.1) (0.11 g, 19%) and methyl 5-(2-(methoxymethyl)-4-methyloxazol-5-yl)-2,4-dimethylbenzoate (compound 2.2) (0.30 g, 52%), both as a yellow oils.
