反应详情

56.6 ml (503 mmol) of hydrobromic acid solution (48% in water) were added dropwise to a solution of 20.5 g (101 mmol) of the 2-methyl-4-methoxy-5-nitro-6-chloro-pyrimidine [Helv. (1958), 41, 1806] in 450 ml of acetic acid and the reaction mixture was stirred at room temperature for 44 hours. It was then evaporated under reduced pressure and the residue formed poured into 500 ml of an ice/water mixture and extracted 3 times with 500 ml of dichloromethane. The combined dichloromethane phases were washed with 100 ml of water and evaporated under reduced pressure. There were thus obtained 16.3 g (69.6 mmol, yield 69%) of the 6-bromo-2-methyl-5-nitro-3H-pyrimidin-4-one as light yellow solid, which was used without further purification.

1. customIt was then evaporated under reduced pressure
2. customthe residue formed
3. extractionextracted 3 times with 500 ml of dichloromethane
4. washThe combined dichloromethane phases were washed with 100 ml of water
5. customevaporated under reduced pressure