反应详情

Combine 2-bromo-2′-nitroacetophenone (10.4 g, 42.6 mmol) with 4-carbamoyl-butyric acid methyl ester (12.2 g, 84.1 mmol) and heat the neat mixture in a sealed vessel at 120-150° C. for about 4-6 h. Cool the mixture, transfer to a round bottom flask with methanol and concentrate. Partition the residue between water and EtOAc. Dry the combined EtOAc extracts over Na2SO4 and concentrate. Initial chromatography over silica gel (EtOAc/CH2Cl2) followed by a second chromatography over silica gel (Hex/EtOAc) allowed for recovery of 4-[4-(2-nitro-phenyl)-oxazol-2-yl]-butyric acid methyl ester (3.05 g, 25%). MS (ES): (M+1)+ 291.1, 292.2 m/z.

1. concentrationconcentrate
2. customPartition the residue between water and EtOAc
3. dry with materialDry the combined EtOAc
4. concentrationconcentrate