反应详情

Free base of the titled compound was prepared from N-(2-pyridyl)-o-phenylenediamine and 4-ethoxycinnamoyl chloride (Lohar, J. M.; Mahsru, U. Indian J. Chem. Sect. A, 1981, 20, 125) 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: 431.45; mp: 169.0-170.0° C.; 1H-NMR (DMSO) δ: 8.78 (1H, dd, J=5.1, 1.4 Hz), 8.18 (1H, td, J=7.7, 1.8 Hz), 7.85 (1H, d, J=16.1 Hz), 7.73 (2H, t, J=6.8 Hz), 7.67-7.61 (1H, m), 7.55 (2H, d, J=8.8 Hz), 7.43 (1H, d, J=7.7 Hz), 7.35-7.22 (2H, m), 7.01 (1H, d, J=16.1 Hz), 6.94 (2H, d, J=8.8 Hz), 4.06 (2H, q, J=7.0 Hz), 1.33 (3H, t, J=7.0 Hz).

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