Carbonocyanidic acid, methyl ester → Methyl 1-[1-(1-Phenylcycloheptyl)-4-piperidinyl]-1H-benzimidazole-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 1-[1-(1-phenylcycloheptyl)-4-piperidinyl]-1H-benzimidazole (as prepared in WO 00/008013, 7.828 g, 20.957 mmol) in THF (200 ml) and HMPA (70 ml) was added dropwise a solution of n-BuLi (1.54 M solution in hexane, 20.4 ml, 31.435 mmol) at −78° C. After 1 hour stirring at −78° C., methyl cyanoformate was added to the reaction mixture at −78° C. After 2 hours stirring, the reaction mixture was quenched with NH4Cl solution and warmed to room temperature. The reaction mixture was extracted with ethyl acetate. The extracts combined were washed with NaHCO3 solution and brine, dried (Na2SO4), filtered, and concentrated to give oil. This oil was purified by column chromatography (silica gel:200 g, ethyl acetate/n-hexane:1/2 as an eluent) to afford 1.53 g (17%) of title compound as colorless foam.

Provenance & Evidence