反应详情

A solution of [2-(1-methyl-1-phenyl-ethyl)-2H-tetrazol-5-yl]-acetic acid ethyl ester (Norman, D. P. G. et al JOC 1999, 64, 9301-9306) (2.53 g, 9.23 mmol) in THF (50 mL) stirring at −78° C. under N2 is treated with a 1 M soluion of NaHMDS in THF (9.23 mL) followed by NBS (1.64 g, 9.23 mmol). After 15 min, the reaction mixture is quenched by the slow addition of water and diluted with EtOAc. The organic layer is washed with water and brine, dried (MgSO4) and concentrated under reduced pressure. The reaction mixture is purified by flash column chromatography eluted with 9:1 hexanes:EtOAc, then 2:1 hexanes:EtOAc, and finally flushed with EtOAc. The desired product, bromo-[2-(1-methyl-1-phenyl-ethyl)-2H-tetrazol-5-yl]-acetic acid ethyl ester, is recovered contaminated with 30% dibromide.

1. customthe reaction mixture is quenched by the slow addition of water
2. additiondiluted with EtOAc
3. washThe organic layer is washed with water and brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated under reduced pressure
6. customThe reaction mixture is purified by flash column chromatography
7. washeluted with 9:1 hexanes
8. customEtOAc, then 2:1 hexanes:EtOAc, and finally flushed with EtOAc
9. customThe desired product, bromo-[2-(1-methyl-1-phenyl-ethyl)-2H-tetrazol-5-yl]-acetic acid ethyl ester, is recovered