1-Bromo-3-chloropropane → 1-(3-chloropropyl)-2-methyl-1H-benzimidazole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred mixture of 13.2 parts of 2-methyl-1H-benzimidazole, 2 parts of N,N,N-triethylbenzenemethanaminium chloride and 150 parts of a sodium hydroxide solution 60% are added 30 parts of 1-bromo-3-chloropropane. To start the reaction, the whole is heated to about 40° C., whereupon the temperature rises to 50° C. (exothermic reaction). Stirring at about 50° C. is continued for 30 minutes. The reaction mixture is poured onto water and the product is extracted with methylbenzene. The extract is dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (90:10) as eluent. The pure fractions are collected and the eluent is evaporated, yielding 1-(3-chloropropyl)-2-methyl-1H-benzimidazole as a residue.

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