反应详情

A mixture of 0.333 parts of ethyl 2-[4-(2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]ethylcarbamate, 1.65 parts of hydrobromic acid solution 48% and 0.11 parts of water is stirred and refluxed for 2 hours. The hydrobromic acid and water are evaporated. The residue is taken up three times in benzene, while each time the latter is evaporated. The oily residue is crystallized from 2- propanol. The product is filtered off and recrystallized from a small amount of ethanol, yielding 0.27 parts of 1-[1-(2-aminoethyl)-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one dihydrobromide; mp. +300° C(dec).

1. temperaturerefluxed for 2 hours
2. customThe hydrobromic acid and water are evaporated
3. customwhile each time the latter is evaporated
4. customThe oily residue is crystallized from 2- propanol
5. filtrationThe product is filtered off
6. customrecrystallized from a small amount of ethanol