反应详情

A solution of sodium methoxide (0.25 g, 4.6 mmol, 3 equivalents), 5-cyano-1-(indol-5-yl)benzimidazole (0.40 g, 1.54 mmol), and cyclohexanone (0.175 mL, 1.69 mmol, 1.1 equivalents) in N,N-dimethylformamide (8 mL) was heated at 130° C. under nitrogen for 12 hours. The solvent was removed by evaporation under reduced pressure, and the residue was partitioned between ethyl acetate (25 mL) and water (25 mL). The organic layer was separated, dried (MgSO4), and evaporated under reduced pressure. Column chromatography of the residue (0.16 g) using silica gel (approximately 5 g) and elution with ethyl acetate/hexanes [1:1] afforded the title compound. (19%) as a pale yellow solid. Rf =0.3 in ethyl acetate/hexanes [1:1]; 1H NMR (CDCl3) δ10.35 (br s, 1H), 8.18 (s, 1H), 8.05 (s, 1H), 7.80 (s, 1H), 7.45-7.43 (m, 3H), 7.21 (s, 1H), 7.07 (dd, J=8.5 and 1.9 Hz, 1H), 6.04 (br m, 1H), 2.32 (br m, 2H), 2.08 (br m, 2H), 1.72-1.60 (m, 2H), 1.60-1.50 (m, 2H); 13C NMR (CDCl3) δ145.7, 142.4, 137.5, 136.7, 130.9, 126.8, 125.7, 124.8, 123.8, 123.6. 122.5, 119.5, 119.2, 118.2, 117.2, 112.7, 112.1, 105.6, 28.4, 25.5, 22.9, 22.2.

1. customThe solvent was removed by evaporation under reduced pressure
2. customthe residue was partitioned between ethyl acetate (25 mL) and water (25 mL)
3. customThe organic layer was separated
4. dry with materialdried (MgSO4)
5. customevaporated under reduced pressure
6. washsilica gel (approximately 5 g) and elution with ethyl acetate/hexanes [1:1]