Reaktion #948124

Reaktionsgleichung

ethyl 1-[(2′-cyanobiphenyl-4-yl)methyl]-2-ethoxybenzimidazole-7-carboxylate

trimethyltin azide

→

Ethyl 2-ethoxy-1-[[2′-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]benzimidazole-7-carboxylate

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturunder reflux for 4 days
3. 3
   EinengenThe reaction mixture was concentrated to dryness and to the residue
4. 4
   workup.ADDITIONwere added methanol (20 ml) and 1N-HCl (10 ml)
5. 5
   SonstigeAfter removal of the solvent
6. 6
   Sonstigethe residue was partitioned between chloroform and water
7. 7
   WaschenThe organic layer was washed with water
8. 8
   Sonstigedried
9. 9
   Sonstigethe solvent was evaporated to dryness
10. 10
    Sonstigeto give a syrup
11. 11
    SonstigeThe syrup was purified by column chromatography on silica gel
12. 12
    Sonstigeto give crystals
13. 13
    SonstigeRecrystallization from ethyl acetate-benzene afforded colorless crystals (0.35 g, 45%), m.p. 158–159° C.

Vorschrift

A mixture of ethyl 1-[(2′-cyanobiphenyl-4-yl)methyl]-2-ethoxybenzimidazole-7-carboxylate (0.7 g) and trimethyltin azide (0.7 g) in toluene (15 ml) was heated under reflux for 4 days. The reaction mixture was concentrated to dryness and to the residue were added methanol (20 ml) and 1N-HCl (10 ml). The mixture was stirred at room temperature for 30 minutes and adjusted to pH 3 to 4 with 1N NaOH. After removal of the solvent, the residue was partitioned between chloroform and water. The organic layer was washed with water and dried, and the solvent was evaporated to dryness to give a syrup. The syrup was purified by column chromatography on silica gel to give crystals. Recrystallization from ethyl acetate-benzene afforded colorless crystals (0.35 g, 45%), m.p. 158–159° C.

Quelle