反应详情

To a mixture of ethyl 8-(benzyloxy)-2-methyl-1-oxo-1,2,3,4-tetrahydro-pyrrolo[1,2-a]-pyrazine-7-carboxylate (5.0 g, 15.2 mmol; Example 32, step 5) and sodium bicarbonate (19.2 g, 228 mmol) in dichloromethane (150 mL) at 0° C., a solution of bromine in dichloromethane (0.5 M, 32 mL, 16 mmol) was added dropwise. The reaction mixture was stirred at room temperature for 2 h, filtered, and concentrated under vacuum. The residue was subjected to column chromatography on silica gel eluted with a hexane-ethyl acetate gradient to provide the titled product.

1. filtrationfiltered
2. concentrationconcentrated under vacuum
3. washeluted with a hexane-ethyl acetate gradient