Phosphorus oxychloride → Methyl 2-chloro-1-[(2'-cyanobiphenyl-4-yl)methyl]benzimidazole-7-carboxylate

Participants

Reaction Steps

A mixture of methyl 1-[(2'-cyanobiphenyl-4-yl)methyl]-2-oxo-2,3-dihydrobenzimidazole-7-carboxylate (8.02 g) in phosphorus oxychloride (30 ml) was heated under reflux for 8 hours. The reaction mixture was concentrated and the resulting residue was poured into ice-water. The mixture was extracted with chloroform. The extract was washed with water, dried and evaporated. The residue was purified by column chromatography on silica gel to give crystals, which were recrystallized from chloroform-methanol to afford colorless needles (2.2 g, 28%), m.p. 154°-157° C.

Provenance & Evidence