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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 894625Generated: October 30, 2026

Calcium Carbonate → Spiro(benzofuran-2(3H),1'-cyclopropan)-3-one, 5-amino-4-bromo-

https://huagongshe.com/reaction/894625

Reaction equation

Participants

RoleNameHCIDCharge
ReactantCalcium CarbonateHCID 10112—
ReactantBromineHCID 24408—
ReactantHCID 12925991HCID 12925991—
SolventCarbon TetrachlorideHCID 5943—
SolventDichloromethaneHCID 6344—
ProductSpiro(benzofuran-2(3H),1'-cyclopropan)-3-one, 5-amino-4-bromo-HCID 3055477—

Reaction Conditions

Temperature-17 °C

Reaction Steps

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.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS04284644
Source datasetuspto-grants-1981_08
ORD IDord-e6844d638f9a4e05aa72564fcbfd7946
Source noteuspto-grants-1981_08