Water → ethyl 4-[[1-[2-(4-chlorophenyl)-2-oxoethyl]-1H-benzimidazol-2-yl]amino]-1-piperidinecarboxylate

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Reaction Steps

K2CO3 (0.129 mol) was suspended in a solution of ethyl 4-(1H-benzimidazol-2-yl-amino)-1-piperidinecarboxylate (0.0347 mol) and 2-bromo-1-(4-chlorophenyl)ethanone (0.0647 mol) in acetonitrile (150 ml). The mixture was stirred and refluxed for 8 hours, then cooled, poured out into H2O and extracted with CH2Cl2. The organic layer was separated, dried, filtered and the solvent was evaporated. The residue was purified by column chromatography over silica gel (eluent: CH2Cl2/CH3OH/NH4OH 97.5/2.5/0.1). The pure fractions were collected and the solvent was evaporated. Part of this fraction (3 g) was taken up in 2-propanone and diethyl ether. The precipitate was filtered off and dried, yielding 2 g of ethyl 4-[[1-[2-(4-chlorophenyl)-2-oxoethyl]-1H-benzimidazol-2-yl]amino]-1-piperidinecarboxylate (interm. 1).

Provenance & Evidence