反应详情

温度

-17 °C

5-Aminospiro[benzo[b]furan-2(3H),1'-cyclopropane]-3-one (0.747 g.) and calcium carbonate (0.47 g.) were suspended in a mixture of carbon tetrachloride (20 ml.) and methylene chloride (5 ml.). The suspension was cooled to -17° C., then bromine (0.22 ml.) was added thereto dropwise, followed by stirring for 45 minutes. The reaction mixture was poured into ice-water, then extracted with ethyl acetate. The extract was washed with water and dried. The solvent was evaporated off, and the residue was recrystallized from ethanol-water. By the above procedure there was obtained 5-amino-4-bromospiro[benzo[b]furan-2(3H),1'-cyclopropane]-3-one as yellow needles melting at 167°-170° C. Yield 0.6 g.

1. extractionextracted with ethyl acetate
2. washThe extract was washed with water
3. customdried
4. customThe solvent was evaporated off
5. customthe residue was recrystallized from ethanol-water