反应详情

Add carbonyl diimidazole (567 mg, 3.50 mmol) to a solution of methyl 4-amino-3-(methylamino)benzoate (586 mg, 3.19 mmol) in tetrahydrofuran (20 mL) at room temperature. Stir the yellow solution at room temperature for 16 hours. Add carbonyl diimidazole (500 mg, 0.96). Stir at room temperature for 4 hours. Add ethyl acetate (75 mL). Wash with 10% citric acid (5 mL), 1N sodium hydroxide (5 mL), and brine (5 mL). Dry the organics over magnesium sulfate, filter, concentrate, and dry under high vacuum to yield a crude yellow solid (690 mg, 100%). Triturate this crude solid with ethyl acetate (10 mL). Filter the precipitate and dry under high vacuum to yield methyl 3-methyl-2-oxo-2,3-dihydro-1H-benzo[d]imidazole-5-carboxylate (422 mg, 64%). 1H NMR (400 MHz, CDCl3) δ ppm 3.46 (s, 3 H), 3.92 (s, 3 H), 7.12 (d, J=8.21 Hz, 1 H), 7.68 (s, 1 H), 7.84 (dd, J=8.31, 1.47 Hz, 1 H), 9.87-10.03 (m, 1 H).

1. stirringStir at room temperature for 4 hours
2. washWash with 10% citric acid (5 mL), 1N sodium hydroxide (5 mL), and brine (5 mL)
3. dry with materialDry the organics over magnesium sulfate
4. filtrationfilter
5. concentrationconcentrate
6. customdry under high vacuum
7. customto yield a crude yellow solid (690 mg, 100%)
8. customTriturate this crude solid with ethyl acetate (10 mL)
9. filtrationFilter the precipitate
10. customdry under high vacuum