反应详情

A mixture of 12.94 parts of ethyl (2-bromoethyl)carbamate, 15.68 parts of 5-chloro-1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one, 10.08 parts of sodium hydrogen carbonate and 160 parts of ethanol is stirred and refluxed overnight. The formed precipitate is filtered off and washed with trichloromethane. The layers from the filtrate are separated. The organic phase is dried, filtered and evaporated. The residue is stirred in 2-propanone. The unreacted starting material is filtered off and the filtrate 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. The residue is crystallized from ethanol 70%. The product is filtered off and dried, yielding 6.5 parts of ethyl {2-[4-(5-chloro-2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]-ethyl}carbamate; mp. 187.7° C.

1. temperaturerefluxed overnight
2. filtrationThe formed precipitate is filtered off
3. washwashed with trichloromethane
4. customThe layers from the filtrate are separated
5. customThe organic phase is dried
6. filtrationfiltered
7. customevaporated
8. stirringThe residue is stirred in 2-propanone
9. filtrationis filtered off
10. customthe filtrate is purified by column-chromatography over silica gel using
11. additiona mixture of trichloromethane and methanol (90:10 by volume) as eluent
12. customThe pure fractions are collected
13. customthe eluent is evaporated
14. customThe residue is crystallized from ethanol 70%
15. filtrationThe product is filtered off
16. customdried