反应详情

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).

1. temperaturerefluxed for 8 hours
2. temperaturecooled
3. extractionextracted with CH2Cl2
4. customThe organic layer was separated
5. customdried
6. filtrationfiltered
7. customthe solvent was evaporated
8. customThe residue was purified by column chromatography over silica gel (eluent: CH2Cl2/CH3OH/NH4OH 97.5/2.5/0.1)
9. customThe pure fractions were collected
10. customthe solvent was evaporated
11. filtrationThe precipitate was filtered off
12. customdried