反应详情

To a solution of 2 g (8.1×10-3 moles) of isopropyl 2-bromo-4-methyl-5-imidazolecarboxylate in 20 ml of benzene was added 1.2 ml (8.2× 10-3 moles) of diazabicycloundecane, followed by 1.0 g (8.1×10-3 moles) of 2-bromopropane. The resulting mixture was heated to reflux overnight, cooled to room temperature and filtered. Concentration in vacuo gave a golden oil. This residue was purified by medium pressure liquid chromatography on silica gel to yield 1.6 g (70%) isopropyl 1-isopropyl-2-bromo-4-methyl-5-imidazolecarboxylate as a yellow oil and 466 milligrams (mg) (20%) of the desired product, isopropyl 2-bromo-3-isopropyl -4-methyl-5-imidazolecarboxylate, also a yellow oil.

1. temperatureThe resulting mixture was heated
2. temperatureto reflux overnight
3. filtrationfiltered
4. concentrationConcentration in vacuo
5. customgave a golden oil
6. customThis residue was purified by medium pressure liquid chromatography on silica gel