反应详情

To a solution of 2-ethoxy-1-[[2'-(N-triphenylmethyltetrazol-5-yl)biphenyl-4-yl]methyl]benzimidazole-7-carboxylic acid (2.2 g) in DMF (10 ml) were added potassium carbonate (0.53 g) and pivaloyloxymethyl iodide (0.94 g), and the mixture was stirred for 30 minutes at room temperature. To the reaction mixture was added water and the mixture was extracted with ethyl acetate. The organic layer was washed with water and dried. After removal of the solvent, the residue was dissolved in methanol (30 ml) and 1N-HCl (6 ml). The mixture was stirred for one hour at room temperature. The reaction mixture was concentrated to dryness and the residue was partitioned between water and ethyl acetate. The organic layer was washed with water and dried. After removal of the solvent, the residue was purified by column chromatography on silica gel to give crystals. The crystals were recrystallized from ethyl acetate-hexane to give colorless crystals (1.13 g. 63%), m.p. 104°-106° C.

1. extractionthe mixture was extracted with ethyl acetate
2. washThe organic layer was washed with water
3. customdried
4. customAfter removal of the solvent
5. dissolutionthe residue was dissolved in methanol (30 ml)
6. stirringThe mixture was stirred for one hour at room temperature
7. concentrationThe reaction mixture was concentrated to dryness
8. customthe residue was partitioned between water and ethyl acetate
9. washThe organic layer was washed with water
10. customdried
11. customAfter removal of the solvent
12. customthe residue was purified by column chromatography on silica gel
13. customto give crystals
14. customThe crystals were recrystallized from ethyl acetate-hexane
15. customto give colorless crystals (1.13 g. 63%), m.p. 104°-106° C.