反应详情

Benzyl bromide (2.33 ml) was added drop-wise to a stirred suspension of (2,6-dichloro-3-nitro-pyridin-4-yl)-carbamic acid ethyl ester (4.57 g) in acetonitrile (40 ml). The mixture was left to stir at RT under nitrogen for 16 h. The mixture was concentrated in vacuo then partitioned between EtOAc (50 ml) and water (50 ml). The layers were separated and the organics were washed with saturated NH4Cl (50 ml), water (50 ml) and brine (50 ml). The organics were dried (MgSO4) and evaporated to a yellow oil. This material was pre-absorbed onto silica then columned on Isco Companion on a silica column (330 g, Redisep) eluting with EtOAc:heptane, isocratic at 10:90 for 1 column volume (CV) then increasing the gradient from 10:90 to 30:70 over 6 CVs. The desired fractions were combined and evaporated to provide the title compound as a yellow oil (6.05 g).

1. waitThe mixture was left
2. concentrationThe mixture was concentrated in vacuo
3. customthen partitioned between EtOAc (50 ml) and water (50 ml)
4. customThe layers were separated
5. washthe organics were washed with saturated NH4Cl (50 ml), water (50 ml) and brine (50 ml)
6. dry with materialThe organics were dried (MgSO4)
7. customevaporated to a yellow oil
8. customThis material was pre-absorbed onto silica
9. washeluting with EtOAc
10. temperatureheptane, isocratic at 10:90 for 1 column volume (CV) then increasing the gradient from 10:90 to 30:70 over 6 CVs
11. customevaporated