Water → HCID 86755689, compound

Participants

Reaction Steps

1-(2-ethoxyethyl)-1H-benzimidazol-2-amine (8.2 g) was added to (±)-ethyl 2-[(3,4-dichlorophenyl)methyl]-4-oxo-1-piperidinecarboxylate (13.2 g) in CH2Cl2 (20 ml). Titanium(IV)isopropoxide (13.64 g) was added and the mixture was stirred for 3 hours at RT. Sodiumborohydride (1.82 g) in ethanol (20 ml) was added and the reaction mixture was stirred overnight at RT. Water (20 ml) was added and the mixture was stirred for 5 minutes. CH2Cl2 (200 ml) was added and the mixture was stirred, dried, filtered, and the filtrate was evaporated. The residue was purified by column chromatography over silica gel (eluent: CH2Cl2 /CH3OH 98/2, upgrading to 97/3). The desired fractions were collected and the solvent was evaporated, yielding 2.6 g of (±)-ethyl trans-2-[(3,4-dichlorophenyl)methyl]-4-[[1-(2-ethoxyethyl)-1H-benzimidazol-2-yl]amino]-1-piperidinecarboxylate (interm. 25), and 6.2 g of (±)-ethyl cis-2-[(3,4-dichlorophenyl)methyl]-4-[[1-(2-ethoxyethyl)-1H-benzimidazol-2-yl]amino]-1-piperidinecarboxylate (interm. 26).

Provenance & Evidence