Methyl Isobutyl Ketone → 1-{3-[4-(2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]propyl}-1,3-dihydro-5-methyl-3-(1-methylethenyl)-2H-benzimidazol-2-one

Beteiligte Stoffe

Reaktionsschritte

A mixture of 5.3 parts of 1-(3-chloropropyl)-1,3-dihydro-5-methyl-3-(1-methylethenyl)-2H-benzimidazol-2-one, 4.3 parts of 1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one, 6.4 parts of sodium carbonate and 200 parts of 4-methyl-2-pentanone is stirred and refluxed overnight with water-separator. After cooling, water is added and the layers are separated. The 4-methyl-2-pentanone-phase is dried, filtered and evaporated. The oily residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (90:10 by volume) as eluent. The pure fractions are collected and the eluent is evaporated, yielding 6 parts (67%) of 1-{3-[4-(2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]propyl}-1,3-dihydro-5-methyl-3-(1-methylethenyl)-2H-benzimidazol-2-one as an oily residue.

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