Lithium Carbonate → 3-Oxo-2,3-dihydro[1]benzothiophene-2-spirocyclopropane

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Reaction Steps

In dry dimethylformamide, 0.5 g of 4-bromo-2,3-dihydrobenzo[b]thiepin-5(4H)-one, 0.6 g of silver tosylate and 0.2 g of lithium carbonate are heated under reflux for 12 hours, at the end of which time the reaction mixture is poured in ice-water. The resultant crystals are recovered by filtration and dried. This crude product is purified by thin-layer chromatography on silica gel (solvent system: benzene-n-hexane=1:3). The crude crystals thus obtained are recrystallized from methylene chloride-n-hexane. By the above procedure there is obtained 3-oxo-2,3-dihydro[1]-benzothiophene-2-spirocyclopropane as colorless prisms melting at 70° C.

Provenance & Evidence