反应详情

A mixture of 2.2 parts of N-(2-chloroethyl)-2-pyridinecarboxamide hydrochloride, 6.6 parts of 1,3-dihydro-1-(4-piperidinyl)-2H-benzimidazol-2-one, 1.66 parts of potassium iodide and 120 parts of 4-methyl-2-pentanone is stirred and refluxed overnight. After cooling, the precipitated product is filtered off and dissolved in water. The solution is alkalized with sodium carbonate and the product is extracted three times with 4-methyl-2-pentanone. The combined extracts are washed with water, dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (95:5 by volume) as eluent. The pure fractions are collected and the element is evaporated. The residue is converted into the hydrochloride salt in 2-propanone and 2-propanol. The salt is filtered off and crystallized from a mixture of ethanol and 2,2'-oxybispropane (1:1 by volume), yielding 2 parts of N-{2-[4-(2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-piperidinyl]-ethyl}-2-pyridinecarboxamide dihydrochloride dihydrate; mp. 165.7° C.

1. temperaturerefluxed overnight
2. temperatureAfter cooling
3. filtrationthe precipitated product is filtered off
4. dissolutiondissolved in water
5. extractionthe product is extracted three times with 4-methyl-2-pentanone
6. washThe combined extracts are washed with water
7. customdried
8. filtrationfiltered
9. customevaporated
10. customThe residue is purified by column-chromatography over silica gel using
11. additiona mixture of trichloromethane and methanol (95:5 by volume) as eluent
12. customThe pure fractions are collected
13. customthe element is evaporated
14. filtrationThe salt is filtered off
15. customcrystallized from a mixture of ethanol and 2,2'-oxybispropane (1:1 by volume)