Methyl 1-[(2'-cyano[1,1'-biphenyl]-4-yl)methyl]-2-ethoxy-1H-benzimidazole-7-carboxylate → HCID 178467365, compound

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Reaction Conditions

Reaction Steps

A mixture of methyl 1-[(2′-cyanobiphenyl-4-yl)-methyl]-2-ethoxybenzimidazole-7-carboxylate [BEC] (228 kg) obtained in Reference Example 5, the residue containing trioctyltin azide [TOTA] obtained in Reference Example 6 and toluene (1148 L) was heated for about 40 hours under reflux (115-120° C.). The reaction solution was cooled and concentrated under reduced pressure. To the residue were added ethanol (764 kg) and sodium nitrite solution (135 kg/460 L) and the solution was adjusted to pH 4.5-5.5 with concentrated hydrochloric acid (about 224 kg). To the solution was added ethyl acetate (735 L) and the solution was adjusted to pH 0.5-1.5 with concentrated hydrochloric acid (about 100 L). To the solution was added hexane (1005 L) and the solution was adjusted to pH 3.5±0.5 with 4% sodium hydroxide solution. The solution was cooled to 10° C. or less and stirred for 1 hour. The crystals were separated and washed with a mixture of ethyl acetate (106 L) and hexane (310 L), followed by hexane (410 L) to give wet MET (396.6 kg).

Provenance & Evidence