Oxalic Acid → (E)-5-Methoxy-1-(2-pyridyl)-2-[2-(3-thienyl)ethenyl]-1H-benzimidazole oxalate

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Reaction Steps

Free base of the titled compound was prepared from 4-methoxy-2-amino-N-(2-pyridyl)aniline and (E)-3-(3-thienyl)acryloyl chloride 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: 423.45; mp: 203.0-204.0° C.; 1H-NMR (DMSO) δ: 8.77-8.74 (1H, m), 8.17-8.12 (1H, m), 7.89-7.82 (2H, m), 7.70 (1H, d, J=8.1 Hz), 7.64-7.56 (2H, m), 7.42 (1H, d, J=5.1 Hz), 7.35 (1H, d, J=9.0 Hz), 7.24 (1H, d, J=2.2 Hz), 7.00 (1H, d, J=16.1 Hz) 6.89 (1H, dd, J=9.0, 2.2 Hz) 3.83 (3H, s).

Provenance & Evidence