反应详情

Free base of the titled compound was prepared from N-(2-pyridyl)-o-phenylenediamine and 3,4-dimethoxycinnamoyl chloride (Ramamurthy, B.; Sugumaran, M. Synthesis, 1987, 523) according to the preparation of (E)-1-(2-pyridyl)-2-styryl-1H-benzimidazole (Example 1, method A). The free base and oxalic acid were dissolved into ethyl acetate. Concentration and recrystallization from ethyl acetate/n-hexane yielded the titled compound. MW: 447.45; mp: 178.0-179.0° C.; 1H-NMR (DMSO) δ: 8.79-8.76 (1H, m), 8.18 (1H, td, J=7.7, 1.8 Hz), 7.83 (1H, d, J=16.1 Hz), 7.72 (2H, d, J=6.8 Hz), 7.63 (1H, dd, J=7.5, 5.0 Hz), 7.44 (1H, d, J=7.3 Hz), 7.34-7.15 (4H, m), 7.04 (1H, d, J=16.1 Hz), 6.99 (1H, t, J=8.1 Hz), 3.78 (6H, s).

1. concentrationConcentration and recrystallization from ethyl acetate/n-hexane