反应详情

To a solution of 3-(4-formyl-3,5-dimethylphenyl)-propionic acid tert-butyl ester (200 mg) and 3,4-diamino-N-(3,4-dimethylphenyl)-benzamide (Example 5-1, step 6) (194 mg) in DMSO (10 mL) was added Yb(OTf)3 (93 mg). The solution was stirred at room temperature for 18 h then the mixture was partioned between water and EtOAc. The aqueous layer was extracted with EtOAc. The combined organic layers were dried, filtered and concentrated. The residue was purified by flash chromatography (amino-column) using hexanes/ethyl acetate (1:4) and gave 3-{4-[5-(3,4-dimethylphenylcarbamoyl)-1H-benzoimidazol-2-yl]-3,5-dimethylphenyl}-propionic acid tert-butyl ester as a red solid. MS (ESI)m/z 498 (M+H). 1H NMR (Acetone-d6, 400 MHz) δ 11.73 (s, 1H), 9.39 (s, 1H), 8.30 (s, 1H), 7.94 (t, 1H), 7.69 (m, 3H), 7.12 (s, 1H), 7.07 (s, 2H), 2.90 (t, 2H), 2.58 (t, 2H), 2.28 (s, 3H), 2.25 (s, 3H), 2.16 (s, 6H), 1.45 (s, 9H).

1. extractionThe aqueous layer was extracted with EtOAc
2. customThe combined organic layers were dried
3. filtrationfiltered
4. concentrationconcentrated
5. customThe residue was purified by flash chromatography (amino-column)