Toluene → 3-acetyl-5-chloro-1-{1-[3-(3-acetyl-2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)propyl]-4-piperidinyl}-1,3-dihydro-2H-benzimidazol-2-one

Beteiligte Stoffe

Reaktionsschritte

A mixture of 5 parts of 5-chloro-1-{1-[3-(2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)propyl]-4-piperidinyl}-1,3-dihydro-2H-benzimidazol-2-one, 10 parts of acetic acid anhydride and 90 parts of methylbenzene is stirred and refluxed overnight. The reaction mixture is cooled, water is added and the whole is alkalized with a diluted sodium carbonate solution. The layers are separated and the organic phase is dried, filtered and evaporated. The residue is crystallized from methylbenzene. The product is filtered off and recrystallized from methylbenzene, yielding 4.5 parts of 3-acetyl-5-chloro-1-{1-[3-(3-acetyl-2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)propyl]-4-piperidinyl}-1,3-dihydro-2H-benzimidazol-2-one; mp. 185.3° C.

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