To a solution of methyl 3-[methyl(propan-2-yl)amino]-2-(4-phenylfuran-2-yl)quinoxaline-6-carboxylate (50 mg, 0.12 mmol) in methanol (30 mL) and water (2 mL) was added sodium hydroxide (19.9 mg, 0.50 mmol) with stirring overnight at room temperature. The reaction mixture was concentrated in vacuo, dissolved in water (30 mL) and adjusted to pH 5 with HCl (3 N). The solids were collected by filtration to afford 3-[methyl(propan-2-yl)amino]-2-(5-phenylfuran-2-yl)quinoxaline-6-carboxylic acid as a light yellow solid (40 mg, 83%).
