反应详情

6-Carboxy-1-(2-chlorobenzyl)-2-n-propylbenzimidazole (200 mg) is suspended in t-butyl alcohol (5 ml), then diphenylphosphorylazide (0.19 ml) and diisopropyl-ethylamine (0.21 ml) are added at room temperature. The reaction mixture is refluxed for 4 hours. Then, the solution is separated into layers using ethyl acetate and water. After the organic layer is washed with water and dried, it is concentrated under reduced pressure. The residue is developed and purified using column chromatography with ethyl acetate/hexane (1/10˜1/3), recrystallized in ethyl acetate/hexane and 6-t-butoxycarbonyl-amino-1-(2-chlorobenzyl)-2-n-propylbenzinidazole (165 mg) is obtained. (Colorless crystals) 1H-NMR (CDCl3, δ): 0.98 (3H, t, J=8 Hz), 1.50 (9H, s), 1.86 (2H, sextet, J=8 Hz), 2.72 (2H, t, J=8 Hz), 5.38 (2H, s), 6.40 (1H, dd, J=1, 8 Hz), 6.95 (1H, dd, J=1, 10 Hz), 7.08 (1H, dt, J=1, 8 Hz), 7.24 (1H, dt, J=1, 8 Hz), 7.28 (1H, d, J=1 Hz), 7.45 (1H, dd, J=1, 8 Hz), 7.66 (1H, d, J=10 Hz).

1. temperatureThe reaction mixture is refluxed for 4 hours
2. customThen, the solution is separated into layers
3. washAfter the organic layer is washed with water
4. customdried
5. concentrationit is concentrated under reduced pressure
6. custompurified
7. customrecrystallized in ethyl acetate/hexane
8. custom6-t-butoxycarbonyl-amino-1-(2-chlorobenzyl)-2-n-propylbenzinidazole (165 mg) is obtained