反应详情

A mixture of 28.8 parts of ethyl 4-(1H-benzimidazol-2-ylamino)-1-piperidinecarboxylate (as prepared in Example XIV of U.S. Pat. No. 4,219,559), 33.9 parts of ethyl 5-chloromethyl-2-furancarboxylate, 15.9 parts of sodium carbonate and 282 parts of N,N-dimethylformamide was stirred for 2 nights at 70° C. The reaction mixture was poured into water and the product was extracted with methylbenzene. The extract was washed with water, dried, filtered and evaporated. The residue was purified by column chromatography (silica gel; CHCl3 /CH3OH 97:3). The eluent of the desired fraction was evaporated and the residue was stirred in 1,1'-oxybisethane. The precipitate was filtered off and dried, yielding 31.2 parts (70.8%) of ethyl 4-[[1-[[5-(ethoxycarbonyl)-2-furanyl]-methyl]-1H-benzimidazol-2-yl]amino]-1-piperidinecarboxylate; mp. 136.0° C. (interm. 1).

1. customas prepared in Example XIV of U.S
2. extractionthe product was extracted with methylbenzene
3. washThe extract was washed with water
4. customdried
5. filtrationfiltered
6. customevaporated
7. customThe residue was purified by column chromatography (silica gel; CHCl3 /CH3OH 97:3)
8. customThe eluent of the desired fraction was evaporated
9. filtrationThe precipitate was filtered off
10. customdried